yes...just like updated drivers are revisions to make lets say video cards better, updated CPU stepping is a revision to make a CPU better, or more efficient so to speak. i'm not sure what stepping entails, but my guess is that they change the traces or pipeline maybe to make data transfer and analysis quicker.
note: if anyone can affirm or correct this, feel free...i dont want to to be quoted on something i'm not 100% sure about.
anyways, P3 700 cC0s are hard to come by due to the limited production right now, so i havent come across many threads about them. however, of the few threads that exist, most reports on the cC0 stepping claim that they produce less heat, thus they are able to OC to a higher speed before reaching the same temp as a cB0 CPU at a lower speed.
now this info isnt totally confirmed and is mostly a matter of opinion right now. for instance, the post by Smbu says he OCed his 700 cB0 to 1GHz w/ a Gorb and its been stable for 4 months. now that is an excellent OC. its pretty much the luck of the CPU at this point. until there are a mass of cC0s on the market to compare with cB0s, there is not telling if there is a vast improvement with the new stepping...