It looks likely that Hillary Clinton will win by a small margin in Ohio tonight. And lose by a small margin in Texas. She is going to speak around 7:45 pm ET and declare victory in the race as a whole.
Barack Obama will then come on around 9 p.m. eastern time and declare victory in the race as a whole. In the end her win in Ohio and Rhode Island will not be enought to keep her in the race and Dean, Pelosi and the Superdelegates will force HRC out by the end of the upcoming weekend.
The Ohio polls close at 7:30 which means that CNN, MSNBC etc. will be releasing there exit poll predictions at 7:31. At that time it is likely that they will declare Ohio for Hillary.
She will then speak before the 8:00 Eastern Time closing of the Texas polls in order to declare victory and state that she is still staying in the race.
Then there will be 2 hours of punditry as her margin in Ohio shrinks from the projection but she maintains her lead and Texas is called for Obama.
Obama will come on right after they call Rhode Island around 9 and give his victory speech in which he claims that winning Texas means the election is all over.
Then follows an evening of punditry.
However, over the next couple of days the uncommitted delegates will flock to Obama due to Hillary's failed "Giuliani Strategy" and it will become imperative for her to drop out to avoid embarrassment. In the end I predict that she resigns from the race by Saturday.
However, I acknowledge that I may be underestimating the Clinton Narcissism and that they may drag this out till April 22 but the above is my best bet.