We just got back from our trip at the end of November. In my previous trip (June 2005) the Nemo ride didn't exist yet (they still had the simulated elevator experience). In the meantime, I hadn't kept up on EPCOT developments and hadn't heard about this ride being built.
On this recent trip, while walking into the Seas I was still expecting the faux elevator. Upon seeing the clamshells, however, I was pleasantly surprised. I'm a big fan of dark rides, and I think EPCOT could use more of them (in light of losing Horizons and World of Motion). I thought the technology was great (especially at the end and on the long screen where you see Crush and the other turtles). Basically, going in with no expectations, I had no room for disappointment.