It should be noted that the first break in Camp Kerry comes from a recent Clinton addition. Who said Bill and Hillary were not working for the Bush reelection. They are not taking any chances on a close election, Hillary wants to run against a non-incumbent in 2008.
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.