There is a lot of discussion about the new mirrorless systems (like the Sony FFF posted above). I think the demise of the DSLR is a long way off still ... a full up DSLR will be the choice of pros for some time to come. At least the mirrorless systems are using a decent sensor since the sensor size is the other BIG thing to worry about (besides the lens ... good glass is vital). Can't get over how much like a toy they look like still though (the mirrorless systems).
A decent article on sensor sizes is at
http://www.dpreview.com/learn/?/key=Sensor_Sizes