I think this is the one being built by guys who were waiting for B17II?
If it is, the multiplayer will be peer2peer based, you can't get a free MP server going. So my guess is 8 guys at once if you want decent connections with no lag and no warping. 32 if you all have DSL and it will probably still be good and laggy.
It was started about 3 months ago, but I haven't heard about any progress they've actually made.
-SW