As Tennant calls time, fans ponder who new Doc will be

David Tennant is calling time on the Doctor Who series at the end of next year.
Tennant's decision brings to an end his popular four-year tenure as the BBC time lord.
The Paisley actor broke the news while collecting the Outstanding Drama Performance gong at the National Television Awards last night.
Speaking through a video link, he told viewers: "When Dr Who returns in 2010 it won't be me. Now don't make me cry. The 2009 shows will be my last.
"I love this show and if I don't take a deep breath and move on now I never will and you will be wheeling me out of the Tardis in my bath chair.
"It's been the most brilliant, mad, life-changing time over the last three-and-a-half years but I am not going yet. Thank you for watching it, for loving it and for being so enthusiastic."
Tennant said co-star Catherine Tate should have won the gong as he accepted the award from Stratford-upon-Avon, where he is playing Hamlet.
Tate, who took to the stage at the Royal Albert Hall to pick up the award for Doctor Who, said: "This is extraordinary. I know Doctor Who has won it every year. I was sweating we were going to lose the year I joined."
Speculation about Tennant's replacement has gripped Doctor Who fans for years.
Cold Feet star James Nesbitt has often been touted as the 11th timelord.
But bookmakers Paddy Power favour Paterson Joseph as the favourite to take over the role, offering odds of 3-1 on him becoming the first black doctor.
He has already appeared in two episodes of the show playing Roderick, alongside previous doctor, Christopher Eccleston.
Life on Mars star John Simm and his co-star David Morrissey in political drama State of Play are also given odds of 8-1 and 5-1 respectively.
Ignored by the bookmakers but a contender that has piqued the fanbase's interest is Notting Hill star Rhys Ifans.