Obviously, it's a pretty strange fact that Apple doesn't offer Blu-ray on its Macs yet, but that will probably change in the not-so-distant future, because Stan Glasgow, president of Sony Electronics US, said they are talking with the Cupertino-based company about the possibility of bringing Blu-ray drives on some Macs.
Unfortunately, we don't know yet if this is going to happen for sure, when, and for what price, but since Apple is so deeply involved into the HD world, they will probably have Blu-ray drives on some Macs, sooner or later. After all, some movies deserve to be kept in your personal collection, and not only rented from the iTunes Store...