It may not have even started yet, but BBC DVD have already released the first part of Series 6 for pre-order on DVD and Blu-Ray! The set is released on July 11th 2011. It looks like we're only going to get two DVD sets this year because of the series split which is a bit of a shame but it can't be helped!
Click the image for the Pre-Order link from Amazon! I think I might order mine now too!