Doctor Who magazine #417 has a complete list of the writers that will pen series 5 of Doctor Who.
Series showrunner Steven Moffat will be penning 6 of the 13 episodes of the series
Mark Gatiss who wrote series 1's The Unquiet Dead, series 2's The Idiot's Lantern as well as played the role of Professor Lazarus in the series 3 episode The Lazarus Experiment will write 1 episode
Toby Whithouse - Being Human creator and writer of series 2's School Reunion will write 1 episode
Simon Nye - 1 episode
Chris Chibnall - 2 episodes
Richard Curtis - 1 episode - the Van Gogh one
Garreth Roberts - 1 episode