The BBC has announced that series 6 will start as usual at easter, but will have a mid-season break, ending on a cliffhanger, returning in the autumn of 2011. This effectively puts Doctor Who back onto it's traditional autumn schedule, last seen in 1989.
Other announcements include the re-commissioning of 'Sherlock'. More details at http;//www.bbc.co.uk/news/entertainment-arts-11124783