SurveyUSA's handy-dandy Electoral Vote counter has Obama defeating McCain 280 to 258 in the general election.
Swing states currently in McCain's column, but within striking distance for Obama (electoral votes in parentheses):
New Jersey (15): McCain 43, Obama 43
Pennsylvania (21): McCain 47, Obama 42
North Carolina (15): McCain 47, Obama 45
South Carolina (8): McCain 48, Obama 45
Florida (27): McCain 47, Obama 45
Missouri (11): McCain 48, Obama 42
South Dakota (3): McCain 47, Obama 43
Texas (34): McCain 47, Obama 46
Alaska (3): McCain 48, Obama 43
Swing states currently in Obama's column, but within striking distance for McCain:
New Hampshire (4): Obama 46, McCain 44
Virginia (13): Obama 47, McCain 47
Michigan (17): Obama 46, McCain 45
North Dakota (3): Obama 46, McCain 42
Nevada (5): Obama 46, McCain 41
A few geographic hot spots:
Virginia (13), North Carolina (15) and South Carolina (8)Virginia is a tossup (47/47), though currently listed in the Obama column. NC are currently McCain states (47/45 and 48/45, respectively). Who can help? Jim Webb can probably deliver Virginia for the Democrats; his military background would help in NC and SC as well. John Edwards might be a possibility as well, although he's said "no" earlier in the primary season. In politics, never say never...
New Jersey (15) and Pennsylvania (21)Both states are in McCain's column, but by narrow margins (43/43 and 47/42, respectively). Local options don't exactly abound, but Hillary Clinton did very well in both states in the primaries (54/44 and 55/45 over Obama in NJ and PA, respectively). Having grown up in NJ, I believe she'd probably swing both states into the victory column, which would be HUGE.
Florida (27) and Texas (34)Hunting for big game? Both states are in the McCain column but within striking distance (47/45 and 47/46, respectively). Obama's big problems in Florida are twofold - the DNC's decision not to seat the FL delegates (and Obama's agreement with that decision), and the Republicans' control of the voting process, as we recall all too well. Hillary Clinton could help blunt the delegate-seating issue (which also helps in Michigan, with its 15 electoral votes). Another possibility is Bill Richardson, who might bring a sizable chunk of the Hispanic vote to the Democrats in both states. One concern with Richardson, though, is that a black/Hispanic ticket might turn off some white voters in other swing states (e.g., VA, NC, SC). Another is that he angered the Clintons and some of their supporters and donors by endorsing Obama - ironically, his endorsing Obama might have hurt his chances at being Obama's VP.
Hillary Clinton has the most bang-for-the-buck as a VP candidate in the swing states, but it remains to be seen if she could be talked into the role. Otherwise, I'd go for Jim Webb. Joe Biden might be a dark horse - he doesn't bring a particular state to the Democrats, but he's experienced and strong on foreign policy, and would be appealing to many of Clinton's supporters. He might bring enough of the benefits of Hillary without the baggage of the Hill-and-Bill show. He also wouldn't require Obama's campaign to pay off over $11M in debts into the Clintons' pockets, which is a lot of scratch to throw away at this stage of the process.