As interesting as this would be, there are too many obstacles:
- People would beat the stuff out of each other unless there was a riot squad.
- As stated before, if held in America, about 3-5% of the 75% or so of Americans would attend.
- 90%+ of Blocklanders are males. Nobody likes a sausage fest.
- Chances are Badspot wouldn't even consider going, nor would most of the beta testers you all want to annoy/rape so badly.
- There is no point to have a convention. The LAN party idea is nice but just as difficult. Why not just have a huge and organized series of in-game conventions. That's do-able with a little effort, and can be very entertaining.