The format was had been very tight coming into this holiday season. So Bluray decided to focus on software sales, and had a TON of B1G1 free sales. This allowed them to manipulate numbers and show that they have sold a lot more titles than HDDVD. Once Warner saw how many Blu discs were moving, they decided to go Blu exclusive.
If you have a 1080p TV, yes. Linder can tell the difference. If you can tell the difference between 480p DVDs and HD broadcasts, you will be able to tell the difference in the HD discs. The HD discs are better quality than the TV broadcasts.
As of right now, the PS3 does not support DTS:MA, which is one of the new HD audio formats. There has been speculation that a firmware patch can fix this, but we have been waiting a year for it. Other than that, I see no reason to get a stand alone player, vs. the PS3 that allows you to play the games.
Bluray will win the war now, before the end of the year most likely. DVD isn't going anywhere in the next 5 years. If you want to get the most of your 1080p system, get a PS3. If not, spend $100 on a HDDVD player.
Yes, I know that HDDVD will lose the war, but players can be had for $100 with 300 and Bourne Identity in the box, as well as 5 in the mail. Throw in the fact that it is one of, if not the best upconverting DVD player on the market, and you can't lose. Besides, you'd spend $60-$70 on an upconverting DVD player anyway. You'd might as well get the HDDVD player. You will be able to find HDDVD discs cheap pretty soon I'd wager, and are just as good, if not better than Bluray.