mythtv / xbmc / boxee...
... not as slick, but 10x more free and powerful.
I'd also say, not for the feint hearted, unless you purchase a ready made setup.
If your fine with a walled garden - a set of restrictions on what you can do with a device - and you don't mind having two devices, one to record your telly and one for music/movies - then Apple TV is fantastic.
Lets face it, most people fall into that category.
But hey, this is El Reg - we're geeks here, right?
Roll your own, you know you want to ...