Yes, I'm quite familar with Apple buying Siri and then using Audience chipset technology, which they apparently have switched from in the iPhone 5 causing a precipitous drop in the stock price of Audience.
If you've read all the posts in this thread you would know that I'm aware of that since I already posted that fact here. But do you really think Apple did not make any changes to the Siri software after they purchased it? And that they didn't couple it with the noise reductions/voice recognition technology they were using?
It doesn't take much of a search for either teardowns of the iPhone 4s and the iPad 2 to find out there is a difference in the chipsets. Or to find out about Audience. And the iPhone 4s with the A5 CPU was released 6 months after the iPad 2 with the same number but with unpublished differences. Do a little exploring.
But Chris is right, none of this matters. It won't be available on the iPad 2 for whatever reason.