Kotaku just posted the info they got from one of the chief designers for the system and it will use a BD-like disc at 25GB with internal harddrive being 8GB Flash memory but allows USB drives for external harddrive capabilities. Disc drive speed is fast enough that it won't need to be full of copied game data like with the PS3 due to its slow disc read speeds.
http://kotaku.com/5809701/wii-u-disc...e-25gb-in-size
Most of the sources are saying the chip is going to be from IBM and either be a 3 Core (majority of sources) or 4 Core (few sources) with each core at 3 to 3.3 GHz.