In adding to what Rock Head has listed, there are a good deal of High Def DVD's already available, it's just that few people know about them and I don't know of any "brand name" players currently manufacturing players.
Do a google search on WMV HD. You'll find T2 (only in T2- Ultimate Edition); Into the Blue and a whole slew of IMAX type documentaries.
WMV-HD is Microsoft Media Player 9's HD codec viewable for the most part only on computers, however there have been a few "no-name" DVD players that are able to play back the format. Such players are also usually the type that "play everything" but don't always play everything "well", which is why you seldom see them in reviews or on the shelves at your neighborhood War-Mart/Target.
I would have loved to see a merger of HD-DVD and BluRay, and at one point it was a strong possibility, but egos were involved so we all lose. The new players will up-convert and output their HD signal via HDMI or a similar digital signal and will only be of use to those who own sets with compatible inputs.
Since I've a third generation Mitsubishi (Component and VGA inputs only) I'm screwed for the next four-five years (until my wife allows me to upgrade). By that time, I expect the technology for scaling current 480p DVDs to have matured, as well as the price to drop.
Keep an eye on Samsung when the new players begin to hit the market. Samsung has announced that since the two camps can't agree on a standard, they intend to manufacture and market a player that supports both BluRay and HD-DVD formats (in addition to being backward compatible with today's DVDs).
On the horizon, Maxell has announced a standard for holographic data storage which will put between 300GB and 1TB onto an optical disc! Talk about uncompressed HD A/V nirvana!
...until then!
