When I first read the headline at Hot Air, I thought he had endorsed Obama, which he hasn't. This is a bit more like the encounters Pat Buchanan had with lefties during the 2004 campaign when they tried to push him to get behind John Kerry. If he doesn't run for a third party candidacy, I'd probably guess that Paul would ultimately wind up endorsing a Bob Barr, who to be honest doesn't look that bad.
I like Paul, but he seems to either not understand or ignore the nuances of American foreign policy and view our country's committments in a very all or nothing light. The world doesn't work like that, but beyond that much of what he says makes alot of sense.