Heard about this from a mate, and went in this morning. When you trade in any game (excluding sports games prior to 09) you can get any of the 4 games above for £5.00.
I traded in Mirror's Edge and Command & Conquer Red Alert 3 and got Bioshock 2 and Dante's Inferno for £5 each.
Not bad considering I paid less than a fiver for Mirror's Edge and Dante's Inferno.
On the receipt Bioshock 2 and Dante's Inferno are £39.99 which are obviously cheaper online. Mirror's Edge and C&C's trade in values are £1.80 and £3.50.
Overll saving of £64.68, happy days.
Deal was in GameStop Bangor in Northern Ireland, this will more than likely be provincewide.
Not sure about PS3 although they definitely had Bayonetta on the same deal.