Well I guess it pretty much depends on what kind of project your shooting for, especially when it comes to
game state broadcasting.
The way I'm going to approach it is something like:
1.) Have a ManagedObject which represents/wraps a jpct-World object(arena, battlefield, dungeon..whatever).
2.) Add a ScheduledTask to that ManagedObject which broadcasts gamestate using a channel(if its turn based/slow just use normal messaging)
3.) Add a ScheduledTask per server controlled object doing things like AI/physics..
4.) Players can join these areas. Every player that joins gets added to the channel to receive gamestate
5.) Per player use a ScheduledTask to poll user input from time to time(using a queue or somesuch)
6.) Per player use another ScheduledTask to do things like physics
I'm currently having a look at sgs too, I just didn't have the time to actually implement jpct serverside yet. So this is pretty much best guess:). In a week or two i'll have a go at it I hope.
I'm pretty sure integrating jpct should be pretty easy, though. I'm a little bit more concerned about the protocol(game state etc)
.