I don't get the impression that the Ring bends one to Sauron's will specifically; more that the Ring bends one to the Ring's will, and that the Ring's will is evil, pure and simple.

If Voldemort gets ahold of the ring, whose ability is that it amplifies power and makes the bearer more evil and Sauron-like (but not neccessarily _serving_ Sauron) I imagine he could handily dispatch Sauron. Of course, the Ring is not destroyed, and as it implants itself into Voldemort he essentially becomes Sauron v.2.0 (3.0?), who now in addition to all of his Dark Lord powers, is now possessed of all of Voldemort's powers and memories as well, a kind of "Saurdemort".

Evil is the only victor in such a scenario, and without a doubt the world would be cast into darkness once and for all.