for people who don't use google (there's a religion where google's the antichrist, no joke):
this is an htpc/streaming media pc. it allows you to stream videos from youtube, hulu, and other free online sources as well as from your PC. it also streams music from pandora, last.fm (without the shitty 360 interface or nasty ps3 browser), and your computer as well. it outputs in full 1080p with full 7.1 surround sound (most computers and gaming consoles can do one but not the other), and features support for third-party subtitles, virtually all major media formats, and a qwerty-enabled remote to dispense of the hassles of a wireless keyboard/mouse setup. it also features an impressive stock of downloadable plugins and applications to extend user connectivity and general usefulness.
tbh, if you don't know what an HTPC is or why you'd use it as opposed to the totally borked 360 streaming interface or the feature-barren ps3 media center option, then you'll probably not purchase it. as someone who deals extensively with digital media (sooooo much cheaper to purchase than hard copies), this is ideal for me. plus, it's impossible to find anything - ANYTHING - that'll stream full 1080p in HD with HD sound for under 350$ while still offering connectivity to the web (aka, not the 360 or ps3). and this is 200$. sign me up!
edit: i forgot the biggest feature - you don't have to leave your tv hooked up to your pc, meaning that long cross-room cables and the noise induced from long cabling runs are gone, too. not to mention you don't have to deal with the hassle of having your tv reset your monitors every time it's turned on.