Time just did a poll.
Clinton vs. McCain
Clinton 46%
McCain 46%
Obama vs. McCain
Obama 48%
McCain 41%
I think as the convention approaches, if Obama is winning in pledged delegates, and especially if he's winning the popular vote, there will be enormous pressure on the superdelegates by the DNC to vote for the front runner. If the superdelegates nominate Clinton when she's trailing in the pledged delegate count, it will be nothing short of party suicide. I think they will eventually realize that, or Howard Dean (DNC Chair) will attempt to make them realize it. :)
Michigan may petition the DNC to allow them to hold a caucus and have their delegates counted. Note that Clinton "won" Michigan's primary, but without Obama or Edwards on the ticket (since it wasn't going to count). If Michigan holds a caucus, this *could* be to Obama's advantage since he tends to do very well in caucus states, but it's difficult to say by how much. Also, Florida is trying to get its delegates counted, but what they're saying is that the DNC will add up the total popular vote from all the primaries, and split Florida's delegates by exactly that proportion (which is looking to be 50/50). Tricky!