As reported earlier, Doctor Who started filming for the new series with new Doctor Matt Smith on Monday and some photos have been released that are putting Whovians and other geeks alike into a frenzy. Yes, as you can see that is new Doctor Matt Smith with Alex Kingston who played Professor River Song in the 4th series of Doctor Who with David Tennant's version of the Doctor in the fantastic two part episode story, "Silence in the Library/Forest of the Dead", written by new show runner Stephen Moffat. She was a companion to the Doctor at an undisclosed future point in the Doctor's life. A companion so trusted that the Doctor told her his real name.
The BBC has confirmed that Alex Kingston has returned to Doctor Who, but who she will be playing and how the character will fit in the Doctor's life has yet to be revealed. It would seem that she will be back for a 2 episode stint.