Matchmaking has changed!

Around a week or so ago I noticed that every game I played seemed horribly lopsided. It seems like every game I play I'm either with or against some really (I hope) new players. Games used to last around 30-40 minutes and be based on strategy and teamwork. Now every game's a 20-some minute stomp that I'd really like to surrender or win as quickly as possible. What happened? I've seen other people writing about the same changes in the same time frame and I've spoken about it with other players in chat. I'd like to see some explanation.