Apart from fixing bugs and introducing tournament play, here is a couple of things that might make the poker experience here more enjoyable.
The pace of the play is sometimes quite low. To improve that you should be able to choose your action before it's your turn. There should be buttons to check, fold, check/fold and maybe call also. Then when your turn comes, if the action you chose before is still suitable you'll do that. You can always fold so thats easy. If you chose check you'll only check if that is still possible. If you chose check/fold, you'd check if its possible and fold otherwise. Calliing before your turn is a bit problematic, because there might be raises after your decision to call.. But theres plenty of solutions for that also..
Another thing to help speed up the play is to fold timed out players. Now they will check if that's possible and that really should not happen.
Another thing that really needs some improvement is the showdown phase. It goes so fast that sometimes there are people asking "why did i lose?" Even if you are paying close attention to the game, you might have hard time noticing what hands everyone had. I think it would be a good idea to post the hands to the chat area after showdown.
And one more UI thing. I'd like to see somekind of slider and/or +/- buttons to adjust the betting amount without needing to type in the numbers.