I don't know for sure about this, but could it be that they were all born on December 25th? I know Annie Lennox was, and I thought I heard something about Jeremy Clarkson being born that day but Rusty Lee I'm really not sure about.
As for the fourth person, I suppose the obvious answer would be Christ......but that is only if my theory is right.
Don't tink it could be this vague as there are loads of other stars (Dido, Helena Christensen, Humphrey Bogart, Jimmy Buffett, Sissy Spacek, Richard Wilson to name a few) who share this birthday and anyways big JC's birthday was never really pinned down to any one date (some say it may even have been in March) and was only laterly celebrated in Dec 25th usurping a pagan midwinter festival.