With the Xbox 360 moving so strongly into the market and the top accessory this year being the $200 HD-DVD drive the battle may be over by year end. There is every chance that there may be as many as ten times more HD DVD players than Blu-ray players in the market by the end of the year - even if you don't factor in that HP, the current leader in PC sales, started shipping desktop computers with a $100 HD DVD option.
My preference was Blu-ray because of its higher initial capacity. HD-DVDs top out at 30GB whereas Sony was able to make 50GB Blu-ray disks (with the possibility of 200GB monsters in the future).
BetaMax, Mini-Disk, MemoryStick, and now Blu-ray. At least Sony is consistent.