I found last years end of year sale to be pretty underwhelming-- it was mostly the same few games that had already been advertised in their other sales. I recall that they had some great deals on sports game towards the end of 2011, but I can't remember if that was part of the end of year sale or not. I remember getting MLB: The Show for $15 and FIFA World Cup for $10.
Honestly though, how are they going to beat the prices they have already had? Crysis, Homefront, Portal 2, Killzone 3, and LA Noire have all already been available at great prices.
The only other games I might look for include: FIFA, NHL, NBA 2K-- otherwise there wasn't too much in 2011 that they haven't already had on sale other than the Christmas lineup of games.
Gamefly has had some good deals this year though-- still enjoying my Tiger Woods Masters game that was $15.