Kerry now has a majority of delegates to the Dem Convention committed to vote for him. HOWEVER, he does not have a majority of delegates who are required to vote for him. Some state laws require elected delegates to vote as pledged on at least the first ballot, other laws for two ballots.
But if Kerry is reduced to his mandatory delegates, he will lose on the first ballot, and thereafter fade into the ashcan of history as someone else is nominated. (After three ballots, ALL delegates will be freed to vote as they choose, regardless of how they were elected.)
Important question you asked.
Congressman Billybob