I think whats great about the genie effect is that it help the user "understanding" what is going on with is window. I mean, for anyone who is really not into computer (see : my mom), the genie effect make the fact clear that the window you minimized is now "waiting" in the dock.
That's the purpose in general of having a great visual desing. Effects should not be put here simply to look cool, they should help informing the user on what's going on.
i've had computer illiterate friends love OS X for features like those.
when they minimize a window, with the genie effect, the can actually see where it is for when they need it later. something as simple as that makes their whole experience better