[Lt Major Burns]

i wouldn't hold your breath for built in blu-ray, to be honest. apple likes to make well-thought out but radical jumps forward, and i think it's a fairly high possiblity that apple may forego Blu-Ray altogether, relying on faster internet and wireless capabilities and plummeting hard disk and solid state storage prices, which are increasingly being seen as the future. Blu Ray would be useful for both backup and for distribution of HD content, but with 8mb broadband becoming standard, and much higher speeds also being available (most companies, certainly here in UK, already offer 20mb speeds at sub £20/month), HD content is already perfectly streamable: i've had 8mb for nearly a year now (i'm currently spending £7.50 a month for it) and apple's recent 720p macworld stream was instant starting and flawless, it's only a matter of months before 1080p streaming content finds broadband speeds to carry it.

As for back up, most home hard drives now exceed 250gb, with many people rapidly filling terabytes now. a mere 50gb is already too small, let alone in years to come. apple has their back up strategy in place already, and it revolves around hard drives and external mass storage.