Players have until the 24th to submit their ideas in-game. I reckon it can take a few days to come up with something worth a guildhouse and a good share of money. I am confident there will be many guilds interested in this.
And regarding the evil counterpart, yes, we are planning one. I'd personally like to see how this one goes first.
If you already got your proposals ready, look for me on IRC #planeshift-gmtalk. I have been offline a couple of days because I had the great idea to install Vista and, obviously, that didn't work. Hopefully I'll be back from the MS realm (with the vista penalty) by tomorrow night.