As far as I know no direct view TV does 720P they all upconvert the signal to 1080I but maybe when the new models come out some will? But there has been some talk over at www.avsforum.com about a "new" Sanyo HDTV at Wal-Mart that might do it? but so far no ones seems to be sure about it. Check the "Big" thread over there about the Sanyo.
I've actually seen the Toshiba RPTVs advertised in the Best Buy ad as displaying 720p natively. At least that is what the Best Buy ad said a few weeks ago. They were advertising the 42" model.