Purely speculation here:
As Gizmodo points out, the new final Cut Pro Studio allows direct burning to BluRay Disc. Problem is, Apple doesn't sell any Blu-Ray hardwareyet. Steve Jobs famously called Blu-Ray "a bag of hurt" because of all of the licensing restrictions, etc. that went along with putting BluRay into Macs.
You could always, of course, buy a Blu-Ray extern
