Once upon a time PCs were marketed as "do it all" work-horses, capable of word processing one minute, crunching stats the next, then finishing the day off by playing games. Now it seems like specificity is the way to go, with manufacturer's desperate to align their products with one particular service or game. Today it's WidowPC and their World of Warcraft gaming PC, apparently the first commercial computer to be designed especially for WoW players. Central to the machine's boasts is an intelligent "Killer NIC" which boosts network performance via a dedicated processor.
Other than that, it's pretty much a standard gaming PC - the usual choice of high-end graphics cards, RAM configurable up to 4GB and AMD Athlon 64 processors from 3000+ upwards. It starts at $1,495, after which the sky is the limit with options. Personally, I always thought that half of the fun with PC-intensive games was building a machine that could handle them, but there's obviously a market for them.