The URL on the poster is also thedarkknight.com where as the other quads use thedarkknightmovie.co.uk
Perhaps it was something knocked together quickly for the premiere (hence the date discrepancy)? Or maybe just a reprint? For the price it went for on eBay, I was tempted to bid as a curiosity, but passed
I'm also curious about those Dark Knight Rises single sided character UK one sheets Bruce has sold a few of. Perhaps the same thing? Single sided for some smaller/one off promotional reason? I'd be curious to see the print quality of small logos and paper feel.