Quite possible.
I really expected Warren to run as Baraq 2.0 but so far it’s not happening and the clock is running. If we get to June or thereabouts, I can’t see it happening. Obama kicked off in Feb 2007.
2008 could prove to be more of a watershed than is even believed now.
The old rules were that a relatively unknown candidate could start early with little money and earn recognition by retail politics, like going from meeting to meeting in each of Iowa’s 99 counties.
The new rules are that one needs to become a celebrity before the campaign starts, and there is growing resentment of any state that is small enough to permit retail politics.
As long as Warren can count on ample money (and she can), she can wait a very long time before becoming an official candidate.