HD I don't know, but several of the CECBs wll run batteries if you build a cord for them. Others probably know the list of the easiest to convert. One clue is if it has a outboard transformer or wall wart it's probably easier to convert if it puts out DC current.
There aren't any factory built HD tuners that are battery operated. You'll either have to go with a Winegard RCDT09A which is a digital-to-analog converter box and forgo HD or build your own HD tuner battery setup like Piggie mentioned.
I've been watching new releases for converter boxes and ATSC set top boxes for some time now and there doesn't seem to be a big hurry to put a new product out there. In fact, some boxes are being discontinued. I don't want to get your hopes down but I just don't see another battery powered device coming out soon.
What specifically are you trying to do? Have you heard about the new mobile standard ATSC-M/H? Within the next year, there will be a bunch of new handheld units coming to the market that'll allow you to receive DTV on the go. Check out posts in here http://www.dtvusaforum.com/mobile-dtv/