As BloggingITGuy points out, HDMI appeals to many people because it can replace six or eight analog audio cables and because you can have more than one such device without extra switching (almost no receivers or processors offer more than one multichannel analog input). Which version of HDMI is a different matter. IF you haven't already, check out the HDMI FAQ in my sig - it digs into the myriad HDMI version issues.

DTS-HD is a particular mess, in my opinion. First, there are multiple flavors of DTS-HD, with DTS-HD Master Audio being the top of the heap (a lossless compression scheme, functionally equivalent to TrueHD from Dolby and the old MLP used on DVD-Audio discs). Unfortunately, there are no source components currently available that will decode DTS-HD MA internally, and very few that will decode the lower forms of DTS-HD. As such, the only way to listen to DTS-HD MA tracks is with an HDMI v1.3 source that can output a bitstream of that signal (which does not include all HDMI v1.3 sources, as early HDMI v1.3 transmitter chips can't do it - the PS3 falls into this category) and an HDMI v1.3 processor that can decode DTS-HD MA.