Hillary is the clear favorite and only enhanced her status with her win last night, but a lot can happen between now and 2008.
I think Evan Bayh has become a more interesting potential candidate with the Democrat's successes in Indiana.
I hardly think she "enhanced her position" by winning a cakewalk Senate race. At this point, I think Obama will win the nomination if he runs, though I would prefer someone more like Richardson. The Democrats are afraid of Hillary and would rally behind the second-place candidate (Obama) against her.
OTOH, if Edwards does very in the early primaries, as he probably will, he may emerge as the main challenger instead.