Well, since I asked for Civ4 as a gift from someone, I decided to go ahead and get AOE3 today.So far, I like it less than AOE2, though I guess that is to be expected as I considered AOE2 to be absolutely fantastic, and this game is quite different in some major ways. That being said, I get the feeling that this game will have longer single player replay value, as AOE2 eventually came down to perfecting a certain build or strategy or two and then falling into the same general patterns in game after game (I can still remember how exciting it was to see the Smush for the first time... a new strategy!? Great!). The chance to play as the Russians is also cool!
(though obviously the game developer's statements about Russia in the history section have a distinctly western bias... until of course good ole Peter starts westernizing, then Russia gets better
Regarding emulation, while it does lose a lot of the nostalgia factor playing it on a PC, I like using them mainly for three reasons. First, because you can pause and save any game at any moment in time, which is not something you can do on consoles. Second, you can keep a window open with a game being played, and still do other stuff, like surf online or download something (I have been doing this lately as I surfed sites looking at Christmas stuff, I play Dragon Warrior 4 in a small window and go back and forth between the game and reading something). And third, playing the games on their original consoles will wear them down and eventually make the games unplayable. So if it's just me playing and there is no need for multiplayer, it's just seems better to use the emulator.