"Instant-on" PCs aren't new. Take a look at the Soyo SY-P4VAL version M
(I think this was on Slashdot before but I don't have a link). The built-in BIOS "media center" software lets you play MP3 CDs, audio CDs, VCDs, DVDs, and watch TV. It's only ~$130, as opposed to $2500 - $2600.
Granted, this article is about a laptop
with instant-on capabilities, which is of course cooler and more expensive.