Yes, it actually will overtake 360 this year actually. If you only look at yearly sales and not cumulative sales.
Reasons why:
1. Its pricecut from late 2009
2. The new system that is slimmer and more quiet/affordable
3. Its growing game database (especially for this year GT5, God of War III, FFXIII)
While people are hoping for Natal or the Sony motion controller to increase sales, its not. People who "own" the systems are hoping more people will buy it to support it. New users won't be buying it just for the Natal/PS3 motion controller alone. Unless these things will change the game industry and the gaming experience tremendously like Nintendo Wii did with their controller, its not going to save the system. Let me point it out again.
Reasons why not:
1. Introduction of motion controllers aren't revolutionary to change the game experience tremendously like Nintendo Wii did. Current users will buy it more than new Xbox 360/PS3 users.
2. New gamers won't buy new systems for the new accessory cause it will add more to the cost of the system. Take Note: People buy systems cause they are cheap, they won't buy them if there are too many other expenses added for accessories. (unless is it less than $60, the price of a game. $80+ is pushing it)
3. More games= more success? NO. More exclusive games= more console sales? maybe a little (depending on what the game is, but some exclusive games aren't good at all)
You need GOOD games to drive sales. (ie. FFXIII, Halo, Call of Duty, God of War, GT, Forza)