Well, Blu-ray sounds nice and all on paper, but the reality is that HD DVD is the much better, feature-complete high def format. Here are some things that HD DVD has that Blu-ray does not have yet (and some it will never have):
* Mandatory TrueHD and Dolby Digital Plus decoding
* Mandatory Picture-in-Picture (real PinP, not fake like The Descent with two encodes)
* Mandatory persistent storage (for web-enabled content)
* Mandatory networking
* HD DVD is region free so you can import virtually any HD DVD in the world
Contrary to what some believe, HD DVD is also 1080p. Virtually all HD DVD movies are encoded in 1080p, and players such as the Toshiba HD-A20, HD-XA2 and even the XBox 360 HD DVD add-on will output in full 1080p. The Toshiba HD-A2 outputs 1080i, but if you have a 1080p HDTV that does inverse telecine properly it deinterlaces and displays the full 1080p anyway.
One thing I like about HD DVD is that it champions next-gen codecs such as VC1 and TrueHD/DD+. Because of this the 30GB is more than enough (just look at King Kong, which is over 3 hours long and gets top quality reviews for video and picture quality). But if you use the age-old MPEG2 codec and lossless PCM (like Blu-ray often does) then you NEED 50GB just to fit it all on the disc. Not very efficient.
Also, I've noticed that there are SO many titles that are released on both HD DVD and Blu-ray, but the HD DVD version seems to get the better audio track much of the time. For example, Flags of our Fathers, The Fountain, Dreamgirls, Mission Impossible I, Mission Impossible II, Mission Impossible III, Payback: Straight Up The Director's Cut, Happy Feet, Superman Returns, Babel, Lady in the Water, The Ant Bully, Phantom of the Opera, and others have the better soundtrack on the HD DVD version with either the lossless TrueHD or DD+ 1.5mbps track, compared to Blu-ray's lowly DD 640 kbps tracks. Blu-ray has managed to pretty much match HD DVD with picture quality for the most part, but I want the best audio too, and HD DVD delivers.
At any rate, the only thing that seems to be keeping Blu-ray alive is the PS3, which is trailing behind the Wii and XBox 360. It doesn't look like it's going to do as well as Sony had hoped, and consequently neither will Blu-ray. This past week Toshiba HD DVD players have seen a ten-fold increase in sales at some retail outlets because of the $100 instant rebate being offered right now (you can get the HD-A2 or Costco's HD-D2 for as low as $249 right now, plus the 5 free movies from Toshiba) and people are really being drawn towards HD DVD. Blu-ray players continue to stagnate, though Sony is said to be releasing a $499 or $599 player this summer. I just don't think that it'll be much competition though for HD DVD, since it's looking like we're going to be seeing $199 HD DVD players sooner rather than later.
By the way, some titles such as Batman Begins and The Matrix Trilogy aren't even out on Blu-ray because the BDA (Blu-ray disc association) didn't get its act together with Blu-ray specs. They've now mandated new specs for all Blu-ray players sold after October 31, which means that practically all current Blu-ray players will be defunct and unable to play any interactive extras on future Blu-ray movies. The PS3 might be able to with an update, but Sony still hasn't confirmed it for some reason. You can read more about it on DVDTown (they wrote an article called "Don't Get The Blues - Say No To Blu-ray). Even some future titles, like "300" and "Blood Diamond" will contain a ton more extras than the Blu-ray version (web enabled features, added game, mobile downloads, picture-in-picture extras, etc).
For me, HD DVD is the way to go.
Don't Get the Blues - Say No to Blu-ray - DVDTOWN.com
Study: Consumers Prefer HD DVD Over Blu-Ray