I was having a conversation with the owner of a local garage almost 2 years ago, and by then all of his guys switched over to cordless. They hardly use their air, and feel that the SnapOn 18V were as powerful as you needed for anything.
I myself however rely heavily on pneumatic tools.
My garage isn't heated, and at winter temperatures, cordless just won't work.
In the summer it gets crazy hot in there, and that's just not healthy for your batteries (they'll work, but it eats a chunk out of their lifetime, and I haven't got the money to keep buying batteries).
That, and electric tools (cordless, or plug in) don't last long in the metalworking environment of my shop.