Nice post.
The key to Saunders LHP issues is that as recently as a month ago, his numbers against LHP were preposterously awful ... I mean, WORSE than the NL pitcher hitting numbers.
In the last month, he has started hitting lefties in a MAJOR way.  I would suspect his home/away against lefties is more fluke than anything -- simply happened to start hitting lefties in a spot in the season where the team got more games at home than on the road.  (Note 7 of his 9 hits against lefties THIS SEASON happened in July)  If my math is right he was 2 for 24 against lefties in the previous 3 months.
Whatever ailed him against lefties ... it ain't hurtin' no more.  And that is HUGE.  The kid has a legit shot at finishing the season over .800 ... with final numbers SUPPRESSED by a 2 for 24 start against LHP!?!  For the first time in nearly a decade, the club looks like it MIGHT actually produce an offensive prospect capable of scaring opponents ... (that wasn't shipped off to the Kansas City finishing school first).

...I'm not ready to proclaim him a 30/30 guy yet, but he IS starting to draw more walks and even out his K/BB issues...and he IS starting to hit lefties hard (it's not just the BA going up...his ISOP is up, his walk rate is up, his LD% is up etc), and he IS a good match for Safeco...
Saunders might actually turn out to be an above-par MLB left fielder...and that would be huge HUGE HUUUUUGE for this team. A partial replacement of Raul Ibanez but with a far far better glove? Yes please.
Now if we could get Smoak hitting and acquire one premium bat to DH...we'd have succeeded in fixing most of the offensive problems (assuming Figgins eventually hits his career norms...he's much better since the "incident")

Mikes' Minor League OPS:
vs. LHP: .787
vs. RHP: .812
 
His GB, FB, LD % are all basically identical regardless of pitcher handedness. 
 
"He'll NEVER hit same-handed pitching" is an internet couch-potato-scout creation.  The reason people said he'd never do it is because he made a quantum leap against RHP in 2008 and 2009 and his LHP skills lagged behind. 

 
2008: .737 LHP, .855 RHP (better)
2009: .702 LHP, 1.049 RHP (wow).

 
But until his 2009 numbers are added up, he was dead even against both.  Dead even and not spectacular, but he was young and raw.  I don't penalize a guy for taking the leap he needs to make against the side he sees twice as often.  Give him enough at-bats vs left-handed pitching and I think he'll come around.  I think he already is, but I expect some more slumps in that regard before it all clicks.
 
I agree with the consensus that his stroke looks better against opposite-handed fellas...but I don't see why he can't be an average hitter against LHP.  He's looked like Shin-soo Choo his whole minor league career.
 
Choo's Minor League OPS ages 22-24 (1000ish at-bats):
vs LHP: .697
vs RHP: .857
 
Career minor league lines through age 23-24:
 
Saunders: .276/.361/.441/.802
Choo: .298/.386/.454/.840 (Choo was the older player and had more minor league ABs)
 
Would you take Choo back in LF?  Cuz I certainly would. Even if Saunders is Choo-lite (which is all I think he will be) a 110-120 OPS+ from the corner again would be welcome.  Putting that position back into Raul Ibanez/Jose Guillen territory with better defense for basically free would be a welcome change.
 
Hopefully Saunders can keep making strides in that regard the rest of the season.
 
~G

All we need from Saunders is above average hitting...not all-star hitting. If we get:
Smoak: 125 OPS+
Saunders: 115 OPS+
Moore: 95 OPS+
Ackley: 85 OPS+ (contact/BB heavy)
In 2011 while Figgins reverts to his career norms...all of a sudden, the line-up looks like:
RF) Ichiro (100 OPS+ with speed)
3B) Figgins (100 OPS+ with speed)
DH) (acquisition or DH or Bradley - ?)
1B) Smoak (125 OPS+)
LF) Saunders (115 OPS+)
CF) Gutierrez (100 OPS+)
C) Moore/Johnson (80 OPS+ combined)
SS) The Wilson Twins (60 OPS+ combined)
2B) Ackley (80 OPS+ with some speed)
That's not a GREAT line-up...but if we could get ther SS position up to 80...it would be enough to win a lot more games.

Ackley will be higher than 85 IMO, but I don't think Smoak is gonna hit 125 next season, so that probably evens out.
 
I still think we need another bat even if that projection came true.  SS will be killing us, C will be killing us, and DH may be as well.  I'm still chewing my hand off about not adding Jack Cust when Oakland cut him back in April.  Having him available when Griffey walked would have been well worth the 2.5 million price tag.
 
But regardless, we need a DH rotation that can club a 110 OPS+.  We can't be posting numbers in the 70s there.  I would still try to keep Branyan if we can't get a steadier option, with the understanding that he cannot play full-time.  Bradley has always hit LHP well, and can still hit LHP better than RHP even in this terrible year.  That's a ridiculously expensive platoon, but Bradley's price tag doesn't give us much option.
 
I don't expect to DFA Bradley, which means he's part of our 2011 DH outlook. 
 
But how would the FO possibly justify bringing back the exact same team that is putting up a historically bad offense this year, with just the addition of Ackley to shuffle it up a little?
 
I think we'd be smart to pay V-Mart, suffer with his bad D (and plus bat) at catcher for a year, then move him to DH and part-time catcher as Moore gets more ABs and both Bradley and Branyan are gone in 2012.  That would increase our offensive potential for '11 dramatically - we'd just have to swallow the price tag and risk a Johjima-like falloff at the end of his contract.  No big, right?
 
And as you say, we're gonna need to do something about SS...
 
~G

Catcher won't be a problem if Moore hits...and he was starting to hit right when he got hurt back in May. All we need at C is something that is not an offensive black hole. I am therefore not remotely in favor of paying for Victor Martinez. Not when we're trying to run a rebuild. I'd rather cough up the money for one of those frequently-available-these-days slugger with a lead glove who's older than 34 but who is still productive types that keep getting screwed in free agency.

I'm down with that option too.  We'd just need to GET one this year, instead of whiffing like last year.
I just don't know that we can afford the major C and SS holes we've had recently.  One hole I can deal with - the NL survives having pitchers hit, so if our SS hits like a pitcher, we can live through it.
But C and SS both being dead zones means we can't have any others, and this year we had about 4 others. 
I'm not optimistic that we can get 4 reduced to zero at the other positions, I guess, and I don't see a SS that we can get to make that position significantly better right now. If we really ARE gonna run 4 rooks and 2nd year guys out there in the starting 9 in Ackley, Saunders, Smoak and Moore we can't also make them be the heart of the order.  Poor Smoak is feeling that pressure right now, and it's stunting him.
I'm not wedded to the V-Mart idea, but I'd definitely consider it.  if our payroll is cut again, though, we'll be totally out of luck in that regard.  We'll make that list of viable bats in the offseason, Matt - see if we can't grab one.
~G
PS - the verification code of "for expletive" is busting me up right now.  I've had too many expletives for the Ms this year as it is...

We need to actually acquire someone who can handle that pressure and reliably post a 125 or 130 OPS+ if we're to stand any chance at all next season. There are usually several. Adam Dunn will be available, for example.
If we could get Adam Dunn and trade for some kind of 80-90 OPS+ hitting SS...well then I'd say we're looking OK.

I wouldn't be opposed to keeping Branyan even if we sign a DH thumper...you could use Branyan as your firs tbat off the bench (like he was used his whole career) and let him steal ABs from Smoak when his back feels up to it to keep the pressure off the kid.

Saunders pulled an outside slider from Francisco Liriano on a 1-2 count to right field for a triple.
Noteworthy because A) Saunders has had trouble covering the outside pitch; B) Liriano went into the game with a 1.08 FIP against left-handed batters; C) it was a pitcher's count; and D) Saunders has been putting some damn fine at bats together against some of the world's best left-handed pitchers.