Not very. Too few players, too spread out. Who knows how many players would have either the means or the desire to attend anyway?
Obviously for logistical reasons, it would have to be held in the "Tax you to death land" of California. No thanks.
More probably Europe - since the SolTech split, Connery + Emerald < Cobalt + Miller. In fact, i'd quite like to meet some SolTech players. They'll be the ones disappearing below the floors, flying through the ceilings, pulling those Matrix moves when you go to shake their hands...would be a joy to behold.
A PlanetSide event at an already-established gathering would probably be more practical. PAX, Comic-Con, etc.
Logistical reasons for DBG, not for the players. DBG Headquarters is in San Diego. LOL Europe??? Oi Vey!
It could be the most successful convention in all history if one were to take place. The planet is the limit.