I shot these pictures of the Pentax K-5 as compared to the Panasonic GH2 to show just how small it is for a DSLR. One of my constant complaints about DSLR's is their ever increasing bulk. Mikes comment yesterday about the K-5 being somewhat "old school" is true in this respect. Pentax have produced a camera that is built like a tank, works really fast and has a true pro spec. in a small package.
DSLR's are derived from 35mm film cameras. The whole point of 35mm was to make it smaller, lighter and more portable than larger format cameras. With the "professional" DSLR that seems to have gone out the window.
Companies like Nikon used to make small SLR's. This is an F2. Their "Pro" film camera from the 1980's.
Their current idea of how a pro DSLR should look is the D3.