Do you plan to develop this further?
As in: Beyond the 4K barrier, to add some user-friendliness, some rules, maybe a bit 'o eye candy?
If so, I’ll continue to host it and link it as a game on our board. 
If there’s interest, I wouldn’t mind doing so… without the 4K limit, there’s lots of functionality that can be added 
Well, sure! I’ve been hosting the 4K version for weeks with no traffic.
Maybe it could be big fun, if you have the time to fool with it. ;D
It’s really too bad you didn’t take the way of a poker game against a smart IA ; I’m sure there would have been a really great interest in it. And making your game multiplayer was not only a greater programmation challenge, but also the gamer interest would have been much less important in my opinion, as most of the time it is difficult to understand how such multiplayer games work…
I know for a fact that the ruling every year has been that you cannot provide arguments with the JNLP. It has been clearly stated before; if was not this year, this is simply a mistake on behalf of the organizers.
How does one go about hosting or joining a server? I’m confused.
In defense of my choice to use arguments on the command line - it is 4 bytes of data, and my jar file is more than 4 bytes lower than the 4k limit. It is also not sound data, art data, game logic, etc, it is configuration only - and I know other games have used the command line for configuration options before, such as whether to run windowed or full screen. That being said, this solution makes it the easiest for those wishing to host a server to do so with the least amount of trouble, and allows players to connect with the least amount of trouble.
That being said, all one has to do to host is a) have an http server up and running, and configured correctly (to host the jnlp file and jar), b) edit the client jnlp file to include your server’s address, and c) either start the server from the server jnlp file or from the command line with java -jar Poker4k.jar. Point prospective players to the client jnlp file, and play on.
Also: You might need to make sure any firewalls and/or port forwarding are configured correctly… the game connects on port 0x4096 (or 16534, for you hex challenged individuals - do we have any of those here?)