The valhalla is going to be the key as Raz mentioned... I do believe it's possible. Maybe not everything for $199, but they certainly can pull off my list for $249 with a condensed motherboard design and still include wifi and a decent sized hard drive.
If they reduce power consumption enough, they might be able to go internal on the power supply and cut down on the cost of an external one as well. That alone would pay for the wifi adapter in a even swap.
I saw a FLASH 64 gig hard drive on sale just last week for $69 bucks... 2.5" format... for laptops... How sweet would that be? ditch the hard drive altogether and go non-spinning media...
I hate trolls.

Systems I currently own: 360, PS3, Wii, DS Lite (2)
Systems I've owned: PS2, PS1, Dreamcast, Saturn, 3DO, Genesis, Gamecube, N64, SNES, NES, GBA, GB, C64, Amiga, Atari 2600 and 5200, Sega Game Gear, Vectrex, Intellivision, Pong. Yes, Pong.