Over at Fight Opinion, Zach Arnold is fearful that Shaw is importing what boxing's doing wrong into MMA. Notable quote:

There are other problems with Shaw's logic as well. Aside from adding perfunctory divisions, the idea that Shaw is adding new weight classes for the health of the fighters is dubious. To some extent, there is truth that more weight classes allows fighters to find a more "natural" fit. They can cut a comfortable amount of weight and still retain all of the energy and athleticism required to compete at a professional level.

However, fighters cut weight to strike a balance: how much weight can I cut and still perform as close to my peak level? How can I leverage my size to my advantage? Thus, there's nothing stopping a fighter from trying to reach the next lowest weight class if they believe the cut calculus ends up in their favor. In fact, Nick Diaz - one of EliteXC's stars who historically fights at 170lbs - actually has to cut more weight to make 160lbs. Again, I'm not suggesting he's not finding the right balance in his particular case. What I'm arguing is that the addition of more weight classes will only marginally preclude fighters from cutting drastic amounts of weight to maximize the use of their weight and size.