Jonathan Bernstein pulls out the binoculars:
The big thing to look for is whether they keep to the timetable or not. If Pelosi says something is going to happen on Tuesday and then comes back and says it won't happen until Thursday, they may be having problems.
The biggest positive sign that might be visible from the outside, apart from keeping the timetable, is commitments to vote yes. I wouldn't pay much attention to commitments to vote no; that's essentially the default bargaining position. But anyone who is in the swing position (wants the bill to pass, wants to vote no) who commits to a yes is almost certainly going to be a yes.
In a blogger confab today, Pelosi sounds bullish.