So far all HDTV television systems around the world, including the DVB system, are based on the MPEG-2 video compression scheme and use as the basis an MPEG-2 Systems defined Transport Layer. This leads to a very high commonality of all HDTV systems in use around the world.
DVB is now underway to include more advanced audio/video compression tools such as e.g. H.264 (MPEG-4 AVC) and later maybe SMPTE VC-1 into its standards. DVB will provide the necessary tools for efficiently broadcasting HDTV in the coming years.
Even if new coding tools are becoming available, Set-Top-Boxes for the new HD standards will be backwards compatible with MPEG-2 MP@HL transmissions and current standard definition broadcasts in MPEG-2.