It's interesting to see Frank Coonelly speak up in today's Post-Gazette in support of a salary cap, but only given his previous job and not his current one. I wrote up a long post at FanHouse on the subject just before the new year began and while I won't rehash every single step of the argument here, I do think that payroll disparity (and thus, a cap) is used as a crutch by uninformed fans and bad owners to explain why their team is so bad. It seems like Coonelly understands that, too, and the tone of his statements is, "I'll support a cap if Selig wants one, but otherwise we're pressing forward in the system as is."
It's not that I think a cap is a bad idea, it's just that a cap would only scratch the surface of what needs to be done in baseball. Time wasted thinking about the cap is time not thinking about getting a leg up on the league in Venezuela or not thinking about draft sleepers or anything along those lines.