A lot depends on the quality of the high speed steel. Cheap Asian stuff, toss it. Amana or other known brands of quality steel, its worth sharpening.
If you've got a good sharpening service, they will usually make a knife much sharper than it was when new. I know guys that will buy new knives from the sharpening service and then hand the knives back over the counter to have them sharpened. It makes a difference.
Not all sharpening services are that good. When I remove sharpened knives from Jamison's Sharpening Service's wrapper, I can shave my arms with the edge. That level of sharpness makes for very easy feeding and a very smooth cut.