People want to know if the new 2.26GHz Octo is faster than the old 2.8GHz Octo since that's what's replaced the other model. I have no doubt that the 2.93GHz (i.e. top spec) Octo will be a good chunk faster than the previous 3.2GHz model but 2.26GHz will be the normal spec for most buyers now as the 2.8GHz model was before.
I don't know if anyone's thrown this out before in this thread but my hunch is that in a few months time they will do a silent update on the Octo Mac Pro line like they did on the MacBook Pro line with the speeds becoming 2.4GHz, 2.8GHz, 3.2GHz.
Maybe they'll be generous and bump them up to 2.66GHz, 2.93GHz, 3.2GHz but judging by the big jump in markup over the previous generation, I don't think they're in a generous mood.
Nevertheless, I'd say expect minor speed bumps at the same price points in 3-6 months time - maybe at WWDC.
I could maybe swallow a 2.4GHz Octo with the current inflated price tag, 2.66GHz at the 2.26GHz price mark and I'd suck up the price increase with only mild discomfort and put it down to the bad economy.
Those speeds already exists. They may not be using the 3.2 due to the much higher listed TDP than the others. Especially since it appears that they have put the CPUs on a daughter card along with the RAM. That had to adversely affect the cooling some.