With the admittedly unfair advantage of 18 hours' distance, I disagree a bit with Mike's assessment. It's true that Hillary lost a potentially productive news cycle--one where she seemed primed to move the ball against Obama on health care--but she more than made up for it in nearly priceless presidential imagery. She looked calm, empathetic, in-command--virtues it normally takes dozens of campaign appearances and millions of dollars in advertising to convey. And while Edwards and Obama both delivered very good speeches at the DNC meeting Hillary had to skip, these speeches were lost in the (more or less justifiably) obsessive coverage of the hostage situation.
Anyway, if you don't believe me, Politico has a piece up where Larry Sabato and Robert Thompson officially certify the day as a boon to Hillary. So that's got to be right... (I noticed Chris Matthews doing basically the same on Hardball last night.)
The only slightly mystifying thing is that leaders normally get points for being calm, empathetic, in-command when they address the public during a crisis, whereas Hillary got points for exhibiting these virtues once the crisis had been resolved. On the other hand, it would have been in bad taste--or, worse, probably interfered with the hostage negotiation--to take to the cameras beforehand, so it's not like she could have done much more than put out a written statement, which her campaign did.
P.S. Here's the video of her statement after the crisis ended:
Update: I see that Mike just weighed in with more or less the same analysis.