There's another (the second) review of the 4th DVD Movie, Into the Wild Green Yonder. The people from DenOfGeek.com has an early copy of the Blu-Ray disc and it says there that the movie is "Not the best outing to date, but at least better than average.".. I've not seen the movie yet, but I'll like to know what's better than more Futurama :P
There are some extras are a little more explained:

• Matt Groening and David X. Cohen in Space: Describes what happened when Matt and David went into a Zero G plane and just how much fun it was
• Docudramarama: "How We Make Futurama So Good". This is quite a funny spoof that is obviously meant to parody the normal "Making Of" featurette that most DVDs incorporate.
• Golden Stinkers: [..] This is the usual deleted scenes, and to be honest, some of them should have been in the movie - especially the extended version of the ship painting scene
• Zapp Brannigan's Guide to Making Love at a Woman: Hilarious in many places, this is short and sweet. It made me wince in places, which is always good humour.
• 3D Models with Animator Discussion: [..] it shows just how much of the movie uses 3D computer generated models and how complex some of them are
• Benders Theatre Etiquette [..] this is a completely pointless and predictable animation. Sorry - but it is

So, some of them look good, the other not so good, but you have to watch the extras yourself to agree or desagree.. I personally need to see the movie, extras and all the other stuff by myself.. but is kinda interesting to have this early review. Don't forget to read the whole DenOfGeek.com article where you can find spoilers and more information.