In an email, Stupak's Press Secretary, Michelle Begnoche, confirms that "[d]iscussions are continuing" between Stupak and Pelosi. Despite the delay of the press conference, Stupak's still trying. These continuing discussions probably show the difficult position Pelosi is in right now. She can't alienate the Pro-Choice Caucus, but she also needs at least some of Stupak's block. She's still trying to find the magic formula for 216. This isn't a done deal yet.
UPDATE: Pelosi has told reporters that there will be "no separate vote" on abortion or anything else for the health-care bill. A staunch negotiating position? A firm guarantee? Is Stupak holding out for an executive order? Will Pelosi try to plug ahead without him, maybe trying to chip away at his coalition?