I don't know what manner of excuse they could possibly have for being just about the only company having trouble developing for the PS3--many publishers and developers, Bethesda included, have a history of successful multiplatform games with huge expansions even bigger than Dawnguard (Shivering Isles and all of GTA IV, for instance), and the system is plenty old enough for a company experienced with it like Bethesda to be expected to make a game with few foreseeable problems--but regardless of reason, Playstation 3 owners require the compensation we deserve.
I did not pay $150 USD for a collector's edition and pick up the game at a midnight release for this crap. Skyrim performs invariably worse on PS3 and now absolutely no one outside of the company (and maybe not even people within Bethesda) know whether DLC will ever be released for it.