any difference for cuda programming using vc 2010 ultimate and professional

We are deciding to buy visual studio 2010, but not sure wether to buy professional or ultimate.
Can somebody teach us what is the difference between them if we are doing cuda developement.

I know for 2008, people need to get two projects, one for c++, one for cu file, then c++ projection call dll of cuda.

What is the current status for cuda supporting between ultimate and professional of 2010?