Sony has released two HD Digital Video Recorders which were announced last fall but this is the first time I've seen them for sale in the US. They look like a couple respectable units, sporting a 500Gb hard drive (at least 60hrs of HD content) for $999 or a 250Gb drive (at least 30hrs) for $799. They feature CableCARD slots so hopefully you could use them with a HDTV feed from someone like Comcast. There's a nice guide to HD recorders on Sony's site as well, hopefully they add a cable system support chart soon.
Personally, I'm counting the days until TiVo releases their standalone HD TiVo with CableCARD support, so that I can get some decent HD broadcasts with a nice easy to use UI.