Kerry being in the race is the best thing the GOP can hope for in 2008. Kerry will smear Hillary, and at the very least the Boston Globe will report some of it, meaning a few MSM outlets may pick up on the Clinton record.
If Hillary goes into the 2008 general election without being touched up by the media, it will be a very difficult fight for the GOP candidate.
Kennedy is Kerry's godfather. Hilary will have to contend with both of them. Watch for some serious ugliness.