Thanks to the Futurama Madhouse, there's already the 1st review of the Futurama Movie 3, Bender's Game... The people from Screen Jabber already has a copy of the movie, and they say that "it's the funniest Futurama film yet".
About the plot [SPOILER WARNINGS]:

[..] Cubert, Dwight and some of their little friends playing Dungeons & Dragons [..] Bender wants to join in and play with the kids, but robots don't come with imaginations installed [..] Bender takes this whole imagination thing a little too far, and develops a slight problem telling fantasy from reality

[..] the price of dark matter [..] has gone through the roof. And guess who controls the supply of dark matter on Earth? That's right, it's the welcome return of Mom Corp

Professor Farnsworth was actually the mad scientist who created an energy crystal that turned all the dark matter in the universe into fuel. [..] he accidentally created an 'opposite' crystal made of 'pure anti-backwards' energy [..] if the two crystals are ever reunited, all the dark matter would be rendered utterly useless, and strange things will happen.

So, according to the review: It's Futurama at it's best, just as we love it, and who can ask for more than that? Oh, and there's a bonus, too. We finally learn why Farnsworth hate Professor Wernstrom so much!. Is nice to read that, because it seems that this 3rd Movie is better than the first 2 (that in my opinion are very good, specially BBS). One of the extras of the DVD is the preview of the Futurama Movie 4, Into the Wild Green Yonder. According to the review, Fry gets killed in the Movie 4... so it looks like a neat history with all the twists that we all like. For a lot of more details please visit the ScreenJabber.com article.

I've updated the info at the Futurama Returns! Movies and Multimedia sections with the info and screenshots of Bender's Game.