I want to point out up front that this is not a 1-star review of the film. The film is an easy 4-stars, maybe even 5-stars, and there are plenty of other reviews here outlining how awesome it is.
This 1-star is for the version of the Blu-Ray that we're getting here in the UK. A version that doesn't include the 90 minute documentary "Assembling the Ultimate Team" or, even more crucially, Joss Whedon's commentary track.
There is no reason for UK fans to be denied this stuff. DO NOT BUY THIS BLU-RAY. The American version is out tomorrow and it's region-free, so it'll work on your player over here. Buy that instead. I am.