This could be very interesting but without some of the "big names" (RE: Google Maps et all) participating I'm not sure it will be more than just a few people participating in an interesting concept open content database.
To use my previous example, if Google dumps most or all of it's map data into this endeavor it gains a tonne of legitimacy. Otherwise your just a little fish in a big ocean of data that people are holding on to and refusing to share.