Well, status on sunday (CEST) 14.00: Custom games are completly dead, nobody is able to host / join games properly. Ladder seems to be broken as well, you have to create a new account in order to find games. Then you may play 2-3 games until you have to recreate an account.
EDIT: If you need any examples of what is/was going wrong, here’s a VOD of WaN who was trying to play cg’s and ladder.