Series 6 begins on the 23rd of April 2011, and then pauses on the 4th of June for what can best be described as a mid-season break. It then restarts on the 27th of August and concludes with the season finale on the 1st of October.
Prior to this of course, is the familiar Christmas Special, which in 2010 is "A Christmas Carol". Very well-recieved by the viewing public, it brings in 10.3 million on the night, rising to 12.11 after a week, indicating a rather prosaic Timeshift of 14.9%.
The series proper, however, shows a continuing increase in timeshifted viewing, now averaging 23%, with some stories only being watched by 74% of viewers on the night.
Ratings-wise Series 6 seems almost identical to Series 2. Average Finals are 7.52 across the board, with "The Impossible Astronaut" approaching 9 million and "Let's Kill Hitler" just clearing 8 million. The mid-season break doesn't appear to have hurt the ratings, but neither has it helped them, unless it has staved off the inevitable mid-series dip. Fan-theories notwithstanding, Doctor Who is still doing very very well.