A Sega/Microsoft/Valve/Sony/etc. needs related wikis to start it up.
Any one of us can help them along, give them ideas, etc. But they have to want to do it for themselves first and foremost; with us as mealy advisers. Otherwise, they may expect us to do everything for them.
as an example, i am currently helping
Kingdom Hearts Wiki (along with some others) start a Square Enix Alliance.
If anyone knows of any other wiki's that may want to start an alliance, please send them my way and i will do my best to help them out.