When the PS3 comes out, you will be dabating whether to play the $19.99 360 version, or the $59.99 PS3 version with little added features. Of course, you can always wait another 9 months after the PS3 version comes out for a price drop. But by that time, Mass Effect 3 will probably be out already.
I don't understand why EA need to drop the MSRP so deeply so soon when they still have a PS3 version coming. A lot of games are still near full price 2 years after released - especially big IP like this.