This is a good move, make her look silly for staying on the field when she should really leave the game. Clinton just became Huckabee:

When the election returns filter in Tuesday from West Virginia, Sen. Barack Obama won’t be there. Nor will he leapfrog ahead to a later primary state, as he usually does on election nights.
Exercising his new-found role as the likely Democratic nominee, Obama will instead travel to Missouri, a general election swing state, to begin laying the groundwork for November. He will do the same next week in Florida, raising money and setting out on what aides describe as a fence-mending bid in the orphaned state.

The travel schedule is just one mark of a candidate eager to shift from primary to general election mode.
Obama and his aides repeatedly told reporters this weekend that the primary is not yet over. But the signs of change were everywhere during the senator’s first campaign trip after a big win in North Carolina and a narrow loss in Indiana nudged him closer than ever to the Democratic nomination.
In a two-day swing through Oregon, Obama purged Sen. Hillary Rodham Clinton from his stump speeches, addressing his Democratic rival only when asked by voters. Obama instead focused solely on Sen. John McCain, the presumptive Republican nominee.