I don't think there's ever been an OS X release that was referred to as an "app pack" even at this stage. Service pack maybe, but this is even below that since all but two of the features showcased so far have been nothing more than new applications. And of those two, one is good (notification center) while the other is potentially Apple's first step towards forcing us to "jailbreak" OS X to make it useful.

That said, the new hardware requirements make me hopeful that Apple might be updating the graphical components of the OS to use OpenGL 3.x instructions, potentially speeding things up a bit. We'll see what announcements follow. I'm personally disappointed that there wasn't any emphasis on optimizing and fixing Lion in this announcement, since I'd assume Mountain Lion would be to Lion what Snow Leopard was to Leopard. But again, this wasn't really a huge announcement. WWDC will probably present us with more information.