I don't have an HD-DVD or Blu-Ray player. I don't really want to buy one until one of the formats is clearly more popular than the other. Whether or not I can manage to wait that long is up in the air. I just don't want to deal with having a bunch of players and a bunch of discs that I can't watch at other peoples' houses or any nonsense like that. Plus, I currently use a PC for all of my TV and movie-watching needs, and I don't even really know what my options are for watching HD movies on a PC, or if I have to get a standalone unit and switch AV inputs. Bah.
I was fortunate enough to start buying movies right around the time that DVDs began to become popular; I only purchased three movies on VHS, and I just replaced those with DVDs and gave them away. The format that will win my heart, and likely the hearts of more American consumers, is probably the first one that can manage to offer movies at roughly the same prices as standard DVDs. Right now there's a significant premium to buy high-def discs versus standard DVDs, though it's decreasing all the time. Probably the most interesting development I've noticed is that the HD-DVD version of 300 includes the standard DVD version. The Blu-Ray version doesn't. So, for about eight bucks more than the regular DVD, you can also get a high-def version. That seems like a reasonable deal, and if I decide to buy 300, I'll probably buy that version.