I was going to get a Hddvd player for my Xbox 360. Not sure if its worth it now as I heard that Warner Bros where only going to make Blu ray discs.On Television I oftern see adverts for movies avalible on Blu ray but never Hd dvd.
I say wait a few more months to see how things pan out, and then decide. Although if you can't be bothered waiting I will suggest that you get Blu-Ray as a significant amount of DVDs are in this format; a lot more than HD DVD.
Currently no one knows, betamax v VHS all over again, however you could look at picking up a PS3 - it's one of the cheapest blue-ray players on the market, and you can play games too....