Valve have released the final set of E3 2010 gameplay clips for Portal 2 today. These final clips reveal the new Gel technologies, Propulsion and Repulsion, that are found in the sequel. One of them makes things bounce, the other is a slip-n-slide.
These are the final two clips in a set of seven E3 clips released by Valve. Part 1 can be found here. Parts 2 and 3 can be found here. Parts 4 and 5 can be found here. The final two clips can be seen below.