I'm not sure I even buy that.
Consider: the corporate sector controls more capital than the private sector, right? But the private sector pays far more total taxes in the US than the corporate sector does. So while marginal rates can be higher, the overall rate of taxation is lower (and dropping, if you can believe that!).
Sure: Microsoft's largest expense is taxes, but then, so is mine.
In fact, I'll go so far as to say that corporations should be the only ones who "pay taxes" -- it'd be a helluva lot cheaper to implement such a taxation policy. Sure, sure, a lot of it would just come out of salaries, but at least individuals wouldn't have to scurry around trying to find tax breaks. Also, there's a certain satisfaction coming from seeing the less-skilled corporations having to pay taxes. Sort of a stupidity tax :~)
/jordan