First this is a great idea, and secondly it would be only ironic if you didn't find someone to help you make this site :P
While I could think of dozens of other neat things to add to this type of a site, I want to applaud you for focusing on the basics to start with. I would say that your description should be a beta version, which you could find a nice handful of developers to join and work improve it. I think the biggest thing is to stay away from developing into Sourceforge or Google Code, which you seem to be focusing on providing a networking opportunity.
While I'm not an official programmer or anything, I'm a designer and developer. I would be willing to assist with this endeavor, because I've got a few other ideas I'd like to find some neat people to work with! My skills would be more limited since I have never heard of Merb, but hey I'm still offering help.
jeremy - gnomeontherun
Educated questions often get educated answers, and simple questions often get simple answers.