The guy who wrote that article is a little behind.
There's a setup script for retroarch:
http://petrockblog.wordpress.com/2012/0 ... pberry-pi/
That gets you:
* Atari 2600
* Doom
* MAME
* NEC PC Engine
* Nintendo Entertainment System
* Nintendo Game Boy Advance
* Nintendo Game Boy Color
* Nintendo SNES
* Sega Game Gear
* Sega Master System
* Sega Megadrive / Genesis
* Sony Playstation 1
This doesn't mean they all run perfectly, of course ... I haven't tried SMS, Megadrive, PS1, PC Engine, or very many MAME games yet. But SNES is definitely playable.
There's a very nice Raspberry Pi magazine here:
http://www.themagpi.com/
Thinking about making that "Steady Hand" game this weekend.