I've been working on some cheap wireless HD solutions using the component > VGA adapter rig with some PC>TV wireless transmiters/converters. Of course it would end up being standard NTSC SD. But check out this new HD wireless:
http://www.snappymultimedia.com/products_hava_hd.htm
I'm really wondering if this thing could work- obviously it is doing some encoding/decoding but for only $250 bucks it might be worth a try. Anyone used one of these? There are a few appearing on the market. It is kinda big, but cracking the box might prove it could be downsized- also it's set up to run on DC so batteries could be employed. Hmmmmmm...