Personally, I wouldn't consider any of the Sony camera a professional camera.
Yes, there are professionals using Sony camera to capture great images.
Yes, they are good cameras.
But, IMHO, professional cameras are either Canon 1D(s) line, Nikon D3 (or D2x, D2h, etc) for 35mm format or Hasselblad (or some other medium, large format cameras).

Likes of Canon 5D, Nikon D300, or Sony DSLRs are considered to be high end amateur cameras, at least to me.

But, they all take great pictures none the less.