I got links and here they are for you:
Short form: the DNA testing was done back in the mid 1990s by Brian Sykes (deep sighs all around, please, because as a source? I do not like this as a source) _and the whole process was filmed_ (lay head down on desk and _cry_, because whatever the story is, I already don't believe it). The full sequence of mtDNA (crying escalates, because anything involving mtDNA is fantastically distant in time) has apparently never been released, leaving us with the extremely generic U5 as the only piece of information (not that it would matter -- in the intervening time, our understanding of the clades has drastically changed. Repeatedly).
Most discussion online based on the first couple pages of google results is astonishingly credulous: in the world of bloggers who take up Cheddar Man as a discussion topic, we're apparently certain that his people were cannibals (hey, maybe they were. No big deal one way or the other to me, except that the quality of evidence being rallied to this argument is kinda crappy, even by the standards of are-they-or-aren't-they-cannibals discussions. To be fair, it isn't just bloggers: http://www.guardian.co.uk/science/2011/feb/16/cheddar-cave-skull-cups. I'm not questioning whether people tooled skulls. _That_ is well-supported.).
At least a few people wrote (if the copy is to be believed, possibly even the LA Times: http://pw2.netcom.com/~duchess/old_stuff/stone.html) with a straight face that the mtDNA shows that a man was a direct descendant of Cheddar Man (cue laugh track). Some of the better posts were at places like genealogy-dna-l (which I saw archived on rootsweb) and similar fora. For example:
It's entirely possible that there is great information out there about Cheddar Man's mtDNA including enough of the sequence to be really meaningful, only it's not showing up in the top two pages of results from google for me because everyone else is just way too enchanted by this whole and he's related to a local schoolteacher! thing. Plus! Cannibals!
But I'm going to give up, at least for now.