There is Dvorak and Colemak both of which on programming workloads "outperform" QWERTY. I am sure that even better layouts could be considered if the entire concept of a keyboard layout was readdressed not just the primary letter and symbol keys. However for most programmers it doesn't seem to be the input device that is limiting the speed of their work but rather their ability to think.

Its well worth playing with Dvorak if you haven't done so and the layout is already well supported. Just don't expect anything magical to happen.