MArcomage

A most interesting feature would be automatic challenging - a player would just tell the system that he wants to play and the system would either add him to "waiting for game" queue or match him with some player already waiting in the queue. In this case you will not be able to choose your opponent.

Also we need think of rules how the system would choose opponent for a specific player. In the new player rating system (EXP based) system would match players that have similiar level. How to match players in current system is a good question.

This is a very good Idea.

How to match in the current system?
Id say pick the opponent by comparable win:loss ratio.

Doesn't the system automatically match the first two players in the queue?
So the queue will always be empty or 1 player waiting...

If not, in my opinion it doesn't matter how it matches, when I want to play, any opponent is fine. Actually, I like to play different players with various kind of decks to experience different kinds of battle instead of one single opponent who keeps on using the same deck again and again.

So I think random matching from available players is good.