“Obama effectively clinches nomination.”

The AP is citing their own tally. Oddly, a hot-off-the-presses email from Team Obama leaves him with still 31.5 delegates to go.

UPDATE:

The AP tally was based on public commitments from delegates as well as more than a dozen private commitments. It also included a minimum number of delegates Obama was guaranteed even if he lost the final two primaries in South Dakota and Montana later in the day.