Don't read on if you don't want to know some of the ideas floating around the t'interweb about what the big 'reveal' about Jack is in Dr Who. I stumbled upon these but they're not really spoilery so I wasn't too upset :D

I'd like to know your take on some of these (the more likely ones obviously, not the way out there never gonna happen ones, included purely because I like a laugh as much as the next gal )

So here they are:

• The TARDIS keeps Jack alive because she loves him (lets face it, he is a manwhore ;) )
• He has been involved/fought in/caused the Time War
• He's not from Earth
• Jack's evil/possessed/mind-controlled by You Know Who
• He has been working for Saxon
• There is another Ten/Jack kiss they just didn't tell us about
• He's the Doctor's son/daughter/mother/father
• He's actually dead
• Jack's son/daughter/mother/father is a former companion
• Jack is Jesus
• Jack and Martha have met before (don't know why this would cause such excitement??)
• Rose has nothing to do with Jack's immortalit
• Jack/an ancestor did something extremely important for the history of mankind
• His real name is something terribly funny/camp/impressive
• He's still a Time Agent/was sent to spy on the Doctor
• He met/travelled with/shagged another Time Lord before/after he met the Doctor
• The TARDIS gave Jack the ability to understand Gallifreyan
• He's a twin/there's a clone
• Jack's not human (JBhas only stated he's no Time Lord)
• He's the Face of Boe
• He's You Know Who (no, not that one)
• He's the 12th/13th incarnation of the Doctor
• Jack has always been You Know Who
• He's a/the TARDIS
• He's a Cylon
• He's Adam/Davros/the Bad Wolf
• Emergency Spare Back-Up Pilot or Embryonic Humanoid-TARDIS
• Jack is being kept alive because Rose is still alive, and when she dies he will either:
  a) die OR b) Lose his immortality
• JB only denied that Jack is a Time Lord. But (and please correct me if I've got my canon wrong) aren't there civillian Gallifreyans too? And JB is enough of a geek to pull the all Time Lords are Gallifreyans, but not all Gallifreyans are Time Lords logic.
• Jack isn't human, he's the Doctor's libido incarnate
• It wasn't the Time Agency that wiped his memories it was a Time Lord/The Doctor

I like the Cylon theories, because proving that -with my limited knowledge of BSG - would mean we'd have to see him a) naked and b) shagging... ;)

What's your favourite? :D

Update: Hubby returns in approx 3 Days 19 Hours 58 Mins according to the clock I do not have on my desktop