Get an external blu-ray player and blu-ray software for the iMac.
I didn't think an iMac could paly them?
What drive would you recommend?
Getting Blu-ray on a new 27-inch iMac | Digital City Podcast - CNET Blogs
Looks like you'll have to go into Bootcamp since there's no blu ray software for Mac yet.
Are there are problems with doing that?