It is clear that he'd likely spend about as much time (or lack thereof) vetting said choices. The nuttier ring wing core support groups are enthusiastically declaring their support for McCain and Palin, but the more moderate ones are expressing concerns for their brand's image:
http://talkingpointsmemo.com/archives/212920.php
The core Democratic partisans are both insulted and incensed; which would be the case for nearly all possible running mate choices (though some are scarier and more experienced, to be sure). But the key, the overwhelmingly negative reaction of the independents, undecideds, and unaffiliated moderates is.... also shock, dismay, and frustration.
As it dawns on them that McCain cannot be counted on as either predictable or stable, as they realize that they cannot count on the Republican party to exercise due diligence in it's own nomination picks, they will flock to temporary support of Obama for no other reason than at least he is reasonable. His choices are predictable, reasonable, and thoroughly vetted. You may not like his choices (I preferred Clark to Biden for running mate, would love Obama to go after Palin and McCain more aggressively that he choses to), but they are predictable, stable, and thorough. Obama is clearly the more presidential of the two men.
McCain's campaign has jumped the shark, and the lead Obama sees in polls today is likely to be the smallest lead we'll see until the days just before the election when the Republicans roll out their traditional October surprise. Obama will win by a landslide (310+ electoral votes and 56% or better popular vote). McCain will go on to lose even re-election for his current Senate seat the next time he runs for it (if he even bothers).
It is time for us to focus on Senate and Congressional races, we need a congress that can work with President Obama to undo the carnage of the Bush administration.
I do not think this is the last we have heard of Palin, however. It is clear she can motivate the evangelical crowd, and she is a good speaker to crowds. I suspect she may go on to Senate seats and possibly another run at the white house in the decades to come. I despise pretty much everything she stands for; but you have to recognize an up and comer in the Republican party when you see one.
Update: For those of you who are impressed by Palin's speech last night, you should be aware that it is 40% blatant lies, 40% uncontested emphasis on her own Christianist agenda, and 20% political sound-bite rhetoric of no substance. Here is a few point by point breakdowns and fact checks:
http://www.cbsnews.com/stories/2008/09/04/politics/animal/main4414049.shtml
http://www.samefacts.com/archives/campaign_2008_/2008/09/palin_v_reality.php
Hat tip to Alan for pointing these fact checks out to me.