I got on for a bit and tried to play while waiting. There were only 240 players online, spread across all the modes. I entered a lobby for "Powered Up Racing" (the game mode only had 56 playing) and waited for a game to start. It started me in a new lobby for some reason, and I sat around for 10 minutes watching the same PSN ids show up in the lobby searching for a game, and then dropping.
There were never enough people in the lobby to start the game, so I just gave up. Stayed signed in to PSN to see if others would switch out games, never happened. Heh.