Chunk is currently exclusive to set 7789 Lotso's Dump Truck. This will be the first time Chunk has been in the LEGO universe.
Minifigure Parts and AccessoriesIt's difficult to tell if Chunk will come as a single piece or if the arms can be removed. The face changes by rotating on an axle, like a roller, revealing 'happy' or 'angry' expressions (as seen here on The Brick Show). The arms appear to be articulated at each shoulder independently. The legs could have articulation, but we can't tell from these pictures.
There's a character in the film named "Mr. Pricklepants". I was hoping it was this gent's name as its so ill fitting. It so happens that Pricklepants is actually a porcupine in liederhosen. Who knew!
Army Building Potential
I imagine the ABP for this figure is low. Unlike the army men, there appear to be no parts or accessories that would be sought after in multiples.
I think if a collector is seeking to fill out a LEGO Toy Story collection, then Chunk has appeal. The face changing feature seems like a neat idea too. Come May 1st we'll just have to see what collectors starts clamoring for.
(Pictures from Amazon.com)