I've got the Sony BDP-S300, FWIW. *And* i have the Toshiba HDA2 HD-DVD player.
The Sony is a good player @ $499, but now that I think about it, the new Panasonic DMP-BD10A is $100 more, but you get 5 free movies in the box PLUS the 5 free with mail in rebate. So yeah, 10 movies AND a Blu-ray for $599? considering movies are usually $30 a pop? I'll take it!
And don't get an 'up-converting dvd player'. I would use the money and put it towards something that actually works. I sell home entertainment stuff at Circuit City, and upconverting players (aside from Oppo's) are a sham.
And neither HD camp is better than the other really. Blu ray has more studio support and about 10 more movies, but HD-DVD is half the price for the player. Luckily, I own both.