UPDATE (8/19/2010) – I received some additional information from our source. The prototype apparently is very early in development because the chip itself is in a box. This may indicate that it is a prototype for a video camera and not an HDSLR.
(Original post from 2/15/2010) This morning, a source has indicated that Canon has a full frame HDSLR that shoots RAW video currently being tested in Europe. Tho the source is new to me, I believe he is reliable. The info is also third hand, but gee, this sure would make a lot of sense for Canon to be developing such a camera.
Tho there isn't a whole lot of detail in the rumor, but supposedly, “very select few high end DoPs” in Europe are currently testing a prototype HDSLR that shoots RAW video. Rumor has it that it is full frame! So it could potentially be the next Canon EOS 5D Mark II (that's my theory – not from the source). This would be serious competition to RED.
As we get more information, we'll be sure to pass it along!
(Photo credit: snap from Canon's site of the Canon EOS 5D Mark II but I blurred it)