I'm not sure if this is a rule of thumb, but I've noticed that exit polls tend to show the more liberal candidate outperforming the eventual results.
Bet half your life savings on these numbers, the other half on Zogby. This is an open thread.
More exits (Chris): There are some other exits out there that show even more favorable numbers for Obama:
Indiana: Obama: 50.5%--49.5% Clinton
North Carolina: Obama 60%--38% Clinton
Since this obviously won't happen, and once again the exits appear to be skewing heavily toward Obama, I'm inclined to go with the "more liberal candidate exit poll" skew theory. That is, liberals tend to vote earlier, probably because many are young (in school), many live in cities (can walk to the polling place), and many are creative class (flexible work hours makes for easier voting time). Also, conservatives tend to use early voting more, and exits only measure the election day vote.