Hmmm, I have bought and received Aperture 3, and whilst waiting for it to arrive, I downloaded the demo, and used the product key supplied by Apple.
I had Aperture 2, but trashed all the Aperture files and app that I could find, and when installing the Version off of the CD, it never asked for any previous version...
I have a feeling it's another of the misnomer's that Apple throw at you, to kinda make you do the right thing! Like SL upgrade!
Another issue to keep in mind, if you should have to re-install you will probably need the full retail of v2 to get the v3 upgrade on.
It seems like a simple question, but I could not find the answer anywhere. Do I need to retain the full version of Aperture 2 after installing the Aperture 3 update version or am I free to sell it or whatever?