Originally Posted by CPT HOOK
I only have the DVD, but I've heard that the "Monster Squad Forever" featurette on the blu-ray is about 10 minutes shorter than the one on the DVD.
DVD = 87 minutes
Blu-ray = 76 minutes
The DVD production was rushed, so the "Monster Squad Forever" cut isn't the final polished cut of the doc, as there's a lot of information that's repeated.
The Blu-ray version is the final tighter edited doc, which actually says the exact same info (with all the repeated bits of info cut out) and also offers some new footage (as chrisac87 stated) and info not included in the DVD version.