Didn't anyone ever see the Adam Sandler movie, Click? It was filmed in glorious HD and released on normal DVD format. Pop it in, check the picture if you've got it.
It's an hour and 40 some minutes long and has an ass-load of special features, and about 30 trailers... so I really doubt that they would need to release this as a double DVD even if it did have interviews and backstage footage. The only reason they would really release a 2-DVD set is if they wanted to take the cheap way out and use dual wimpy DVD-5 discs rather than a hefty DVD-9 disc.