Interesting. I hadn't been following HTPC for some time now as I don't need what it brings to the table. Currently I use my MacBook Air to put some things on my Plasma by mirroring the screen with a mini-display port to HDMI connection. For the little I need it for it works well. Only downside to me with this is that sometimes you have to plug and replug the darned connector at the computer end to get the HDMI handshake to cooperate. Once it does it, it holds quite well and operates just like the desktop.
Note that you can rip BD and play them on a Mac, or at least I've been told I can. You just can't play the disk straight up, even if you use an external BD drive. One of these days that might change, but Jobs isn't fond of BD...