Blu Ray

Simple: Set up a Boot Camp partiton, install Windows on it, and boot into it when you want to watch a BD.

Or, you can take the cubersome and illegal-in-the-USA route and use a Blu-ray ripping program to rip the disc to your hard drive, then play it back with something like VLC.

Apple is hellbent on killing the optical disc. There will never be native Blu-ray playback support on the Mac, and I suspect that with the next major revision of Mac hardware, the internal optical drive will be gone altogether.

If you have a Blu-ray drive then buy a Mac Blu-ray player like
http://www.macblurayplayer.com/

If you have a Blu-ray drive then buy a Mac Blu-ray player like
http://www.macblurayplayer.com/

That product is just a hack of a Blu-ray ripper and VLC rolled into one:

http://www.macblurayplayer.com/opensource.htm

The encryption in Blu-ray movies is much more complex than in DVDs, and as such there's no "universal decryption" algorithm for it -- at least, not one that's been reverse-engineered and made free -- so such products that rely on current open-source efforts will only be able to play the Blu-ray discs whose keys have been exposed. You'll still run into a decent number of movies, especially new releases, that just won't play because they can't be decrypted. Commercial, legitimate Blu-ray players (both hardware and software) have to pay the motion picture industry royalties to be given access to the mechanisms to properly decode discs.

You can download it and try it out for free before paying for it