I watched all the special features, aside from the commentary, last night. Thoughtz and detailz:
• Deleted scenes: Great collection of these. I think there was around 9 minutes? David's cameo is found here. He was originally meant to sing over the sex/shrim scene.

I will not spoil any more.
• Extaaaanded scenes: Will F's scene is LONG. I'm talking 15 minutes long! From entering the office to Will running from the mall, it's hugely expanded. It's almost like a short film. Lots more Top Gun, more floppy disc jokes, more "money" lines. Overall my favorite deleted bit. There is also more stuff with T&E in their celeb crib. Eric's "mom" has a short scene. Apparently she smells like shit.
• Good Evening S'wallow Valley: 8 minute interview piece. Some gags and goofs. Interviews with the supporting cast. Doug Foster, of Check It Out and the Sleepwatching Chair commercial is hilarious. He gets a little too comfy in the interview, thinks he has crossed the line in talking about T&E (he didn't) and then he gets all reserved and takes back what he said. Really funny moment.
• Interview with T&E: Super long 22 minute interview, which is the uncut raw footage from the next feature.
• HDNet: A look at the movie: 4 minute promo from HDnet with bits from the interview above.
• Promos: Really great collection here. They have the YouTube promos leading up to the release. So it has the awesome NACA Challenge video. Also has the Sundance interview where they talk about being Rango'd. Also includes a few more YouTube vids.
• Shrim screensaver: Shrim dance on loop for 4 hours
• Poster and production photo gallery: A lot of black and white set photos. Also four posters.
• Red band AND green band trailers