Game On is a video game event due to be held in London. You will get a chance to play PS3, Wii and XBOX 360. Not only those, but current gen and retro. Wii and PS3 will be availible to play on the 29th Wednesday November.
Personally, the chances are I might be going. Argh, this is disgusting, they have to make you choose which one you want to play Wii or PS3, only one. DAMN. I'm going to go for PS3 since it's releasing in March, and I will have a Wii in my hands in a few days.
Source: Games Industry
Official Site: Game On