well firstly, you said its HD ready unless you get the elite, but now you are referring to the ability to play a HD disc format? lol..well the elite never could do that either without the seperate drive....well the xbox needed a hd dvd drive addon to play hd dvds but they dont even make them anymore.
at least with the ps3 you get the best blu ray dvd player money can buy
why?
cos its the only blu ray player that get software upgrades so you get all the new features
but that aside:
are we wanting a games console or a movie player?
both consoles will deliver their content in HD (ie, the games...without the need for upgrades - bar a £5 HDMI cable perhaps depending how you want to connect to your TV).
For what its worth, their will be a Bluray device along for the 360 in the future, but personally I beleive unless you have a 1080p 40'' + TV its not worth it.