I think they turned the old Siri app off. I had it, and it did not work very well, not like the one on the 4s. I know with Dragon Dictation I could dictate a note, but not a text.
I went for the 4s, since my old 3gs wasn't cutting it anymore, and I was warned about upgrading it. It has only been 1 1/2 years, so I upgraded using DS eligibility - he has my 3gs.