just got back from two days in the wilderness with no 3g, so i am just now hearing about this pick.
my analysis (caveat : i'm not a Romney supporter, so that may affect perfect objectivity)
pros :
Ryan is extremely well spoken, and can debate quite well.
it's early to say, but if he could flip Wisconsin, that's ten electoral votes that went Obama last time.
conservatives love him, and he'll certainly cause some voters who would have otherwise stayed home to show up and pull the lever for Romney.
his tax plan is a big plus for a small percentage of people who have vast amounts of wealth. it's likely this pick will bring in an incredible amount of money from donors who may have previously written this election off as lost due to Romney's lack of affability and complete disconnect with the average voter.
cons :
Ryan's budget. i'd wager that many retirees (even some conservative retirees) aren't willing to trade the medicare benefits that they've paid for their whole lives for a lousy private voucher system. even if this is unlikely to actually happen, this election is now about privatizing medicare and part of social security.
Ryan's tax plan is a liability with voters who have seen tax cuts for the top percentages fail to deliver over and over again.
again, while it's early to make this prediction, this pick may cost Romney Florida. that's 29 electoral votes down the drain, unless the pick really does bring in enough money to saturate Florida's airwaves 24/7 between now and the election with anti-Obama rhetoric.
summary :
it was either Ryan or Rubio. Rubio might have brought Florida with him, which would have been priceless. additionally, Rubio's Hispanic heritage would have an asset to Romney in bringing out a bit more of the Latino vote which will likely go Obama. Ryan brings money from donors and rock solid conservative credentials. the other names being floated were non-starters who would have brought very little to the campaign. between Ryan and Rubio, it's my opinion that Rubio would have been the better pick.