Well... It has pros and cons...
I'll start with the pros:
Great way to avoid a mass flood.
Faster dispute of TC
You know when the tourney is about to begin, started and finished
Cons:
When you decide to make a server and make a global after you pressed the join when there is a space button, you might forget to set an owner pass and leave the server
If there are only 12 spaces in a room but 30 press the button, what will happen?

bump... Because I'd love to see this ;o
Especially during times like these when there's a whole lot of people online. Would help a lot. Maybe even show a "You're number ## in the queue" when trying to join a full server?