Hope you don't mind if I chime in with a few reflections; Tyros 2 has not only the new SA voices: many of the other sounds as well have been re-sampled. I have read on the Yamaha website that, to record the new strings, they hired members of the James Last orchestra (and this makes me think that the recording sessions happened in Germany). This means that the T2 is different from evey other keyboard on the market, including the T1.
You know what I mean: the PA1X pro has many of the Triton sounds, the G-70 has many of the Fantom X sounds, some V-accordeon sounds and the organ sounds of the VK8, and I agree that they both sound great, but here we are facing something new, that took a great effort, even from a financial point of view. So, if you ask me if I think that it was worth the while to pay what I paid for my Tyros 2 (and I still have to sell my Tyros 1), the answer is "yes", but to each one its own, I guess...
Speaking of styles, the 100 new styles have never been released before and so they are really "new"; of course soon they will be available on the net, like happened for the Tyros 1, but only the Tyros 2 can take advantage of their programming subtleties (many of the strumming guitars now sound completely different, because they make use of the SA sounds).