There's a "lost episodes" DVD that will be released soon. Link:

http://shop.comedycentral.com/Chappelle-s-Show--The-Lost-Episodes---Uncensored-DVDs_stcVVproductId5218512VVcatId426836VVviewprod.htm

Also, Comedy Central is scheduled to begin airing the 4 filmed episodes that would have been the start of season 3, on July 9th. It appears that 1 of the new shows will air each week. Link to schedule:

http://www.comedycentral.com/tv_schedule/index.jhtml?seriesId=11616&forever=please