Dr. Who is not exactly hard to replicate with almost any system, you just need to give the Dr. a special regeneration power with simple and wooly rules, and lots of bonuses to repairing / fixing things (plus a sonic screwdriver with huge equiptment bonuses!). Most of everything else is mundane. I tcould probably be run in Coda easilly enough or World of Darkness, to keep it simpler!
I'm relieved and excited to hear that the new Doctor Who show has been good. I haven't been able to see it yet, but look forward to the day when I can.