I will advance one radical theory: Sarah Palin has more experience in one respect than the three other top dogs combined (edited to add: unrelated to the governorship). She has held a job in the private sector for about 8 years. I can respect that. And fairly gritty jobs at that.
Otherwise I really don't have much to say that isn't being covered everywhere, so I'll summarize:
Every right-wing blog: "This is pure tactical genius. McCain and Palin's ovaries will march to the White House like Sherman to the Sea."I'm also in the wait and see camp.
Every left-wing blog: "She has no experience and she hates women and homosexuals."
Every libertarian blog: "Errrrm. Wait and see?"
Pros: fought corruption and pork barrel spending successfully, decent energy policy including support for drilling, NRA membership, pro school choice, pretty good fiscally, approval rating in home state between 80 and 90%.
Cons: inexperienced, total blank slate on foreign policy and (non-firearm) civil liberties,* backed creationism in schools.
I'm putting youth in the neutral category because it could make her seem vital and energetic, or it could underline McCain's creakiness, or it could just catalyze the inexperience critiques. Tactically the inexperience may be an issue or a huge issue because it's a minefield for both camps. I'm waiting to see which side can play this smarter.
Superficially: A young, attractive mother married to her high school sweetheart with lots of kids, including one in the Army and one disabled? The cameras will eat that up. For the shallow voters out there you can capture or neutralize some of the people who backed Hillary just because of her homogametic chromosomes and some of the white guilt crowd that would have voted for Obama just for the sake of history.
Nick Gillespie has some very important leaked documents from the McCain campaign which shed light on their process. I think they may have under estimated Emeril's appeal to middle aged women, however. Personally I was holding out hope for the Motor City Madman himself, Nasty Ted Nugent.
Penultimate thought: Does she kind of remind anyone of Laura Roslin/Mary McDonnell? Should that be played up to secure the crucial geek vote? Would we even want a VP who reminds us of President Roslin? I will have to mull this over further.
Final thought: has this pick completely wiped Obama's address off the radar? I've only seen three posts in my feed reader all day about his speech, none positive. Twelve hours ago the Internet was gushing forth praise. This might be very savvy on Team McCain's part, but given their history I'm thinking it's at least partly serendipitous.
Post final thought: Periodically checking things on Palin's Wikipedia page you got to see the thing being re-organized and edited and improved in real time. Occasionally I still wonder that Wikipedia can manage to be so plastic and so stable at the same time. It's an impressive feat.
* I pretty much ignore the gay marriage debate at this point because I think the whole thing is drawn up on ideological lines that are entirely orthogonal to how I see things.