For all you Clara haters,there are quite a lot of you, will be happy to know that Jenna Coleman has been confirmed to be in all of Series 9 of Doctor Who. Steven Moffat made that announcement last week at the launch for Last Christmas.
"Jenna is in all of the next series, which we’re delighted to reveal."
I'm happy that Jenna Coleman will be coming back as she and Peter Capaldi have great chemistry together. So she will be in 12 episodes if they continue with the same formula as this year and that will also make her the longest serving companion of the new series.
Source: Radio Times