When will I buy a PS3?

Ok I will buy a PS3 at some point, kind of want to buy one now but I simply cannot justify the purchase £425 is alot of money.  The only games I want for the PS3 which are not on or coming to 360 are resistance and motorstorm.  And while I want them they are games I can wait to play.  The only game I am really looking forward too which looks like it prob will be a PS3 exclusive is MGS4 and it looks like it isn't coming out this year. 

Is there anything coming out in the next 3 or so months that I could use to justify the purchase?

As soon as their library gets better. I don't care about the price, I just want them to justify it with content. The value of the hardware means nothing if there is nothing compelling to play. Their library is below mediocre at the moment for what they are asking.

There are many people here that claim that the 360 is just as expensive as the PS3, but the 360's current library is far superior thus justifying the price to me.