It seems that Apple’s iTunes 8.2 may have support for Blu-ray as indicated here by the screenshot of the About screen from 9to5Mac. The support may just be Gracenote support though. This doesn’t really make a whole lot of sense, though, as iTunes would be able to identify a Blu-ray disk but not be able to actually play it back.
I really wouldn’t be surprised to see this actually pan out to be full-on Apple Blu-ray support. We’ll just have to wait and see. In the meantime, you can think about picking yourself up a Blu-ray drive.