Well, it's a superb Blu-ray package - three discs; the extended movie (all 3hrs 6 mins of it), special features and a digital copy for iTunes or PC.
DTS MA HD soundtrack is awesome (sofa-shaking stuff), and the picture is gorgeous - lots of colour and detail, with (of course) tons of dark scenes with inky blacks and shadows that'll be tough for some systems to pull off well.
Longer review next week when a) it's not my day off and b) i've had a chance to compare the US Director's Cut version with the UK release.
Film itself has its flaws (especially if you're a zealous fan of the graphic novel), but is such an all-out spectacle that I really enjoyed this extended edition.
Just a word of warning if you haven't seen the film and have kids- this isn't family friendly entertainment! Sex and graphic violence aplenty....