I forgot if they're going to use both, but I do remember Vivid Entertainment is going to use HD-DVD. Imagine that...now you can wank off to 1080p boobies.
I find sound to be far more important then video. HD video is nice, but sound, well, it really limits the whole experience altogether. HDDVD all the way. Blu-Ray ftl.
Yeah I'm happy with the picture quality I get, if I could find a player that supports DolbyTrueHD be it blu ray or HD dvd then I'd probably get on (if the price is sensible!)