The Canon EOS M was only just announced, but there are some hands-on impressions already floating around. The camera marks Canon's first attempt at a mirrorless interchangeable lens camera, and they've gone with a very subtle design both in the body and the new EF-M lenses. Sebastian over at cinema5D was invited by Canon to a pre-announcement event last week, and was able to play with the camera a bit. He gives some of his impressions and his overall feel of the camera below.
In terms of the sensor inside, it looks like it's going to suffer from aliasing and moire just like the previous Canon cameras (with the exceptions being the new 1D X and the 5D Mark III):
Most significant for HDSLR people is the fact that the EOS M incorporates the same sensor the Canon EOS 7D& 650D also share. Yes the EOS M has the 7D sensor again meaning it also has the same aliasing & moiré issues.