Unite13 is being held in Vancouver this year. This means Unity users from all around the world will be traveling to Vancouver to attend the main Unity conference. We've had someone reach out from Texas suggesting we host a meet-up so we could all meet and mingle. I think this is a great opportunity to meet other Unity users from around the globe!
I think the format will be just chatting and mingling with maybe a few introductions.
Keep in mind Unity holds a "real" party every year during Unite where all attendees can go, mingle, and drink heavily :). This is just pre-event networking.