According to the AP, it’s over:
Barack Obama effectively clinched the Democratic presidential nomination Tuesday, based on an Associated Press tally of convention delegates, becoming the first black candidate ever to lead his party into a fall campaign for the White House.
[…] 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.
Good. Now we can get on to the business of kicking John McCain’s ass.