it is very notable that clinton is NOT out campaigning for kerry, nor has he been prior to his surgery.
it is of course possible that kerry's ego will not let clinton get involved in this, but maybe bill hasn't offered.
Hard to figure if clinton's tremendous need for public attention would outway any fig he may care for HRC's 08 prospects.
Bill and Hillary win either way. If Kerry were somehow to win, Bill would look like some sort of kingmaker (as he portrays himself to already be). If Kerry loses, Hillary is out front for the nomination in '08, and he wields power from behind the scenes, much as she did in the Oval Office during the first Clinton administration.