yep if you render using hardware 2.0 as your render engine curves will be displayed. If you have objects selected you will even render the green selection highlighting.
You cannot disable curves from rendering, that I am aware of, but you can do as stwert suggests and uncheck show > NURBs curves
or
You can put all the curves in your scene onto a layer and then simply make that layer not visible before you render.
"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675