This exclusive version comes with extra DLC, including the "Maw of Despair Outcast Pack" (wow, free despair!) with a co-op map and multiplayer skin, the "Echo Scrapyard Rifter Pack" with a new "Homeworld," and another multiplayer skin. You'll also get a PS3 theme featuring Starhawk concept art, a soundtrack and ... oh yeah, a PSOne Classics copy of Warhawk.
If you were going to get this anyway, and especially if you were going to shop there anyway, this is a pretty great deal. If not, you still have until May to figure out whether it's worth jumping shop.