It'll be EU based, as I'm in England. I guess the latency may be too bad for America though.
Round robin means that everyone plays everyone else and are scored on total number of wins. This is under discussion at the moment as it's been pointed out that if we have more than ten teams (likely) then each series will be fairly long. We're considering the possibility of (if we are successful enough) making the second series a ladder, if there's enough interest.
I'm going to be adding a google docs spreadsheet to the first post tomorrow, so people can sign up and give me a rough idea how many I'm dealing with.