I know Nintendogs only from videos and images, but in a way, I guess, you could consider it as one of several early predecessors to what Aibos are nowadays. But I must say: having lived with my 1000 now for already about three quarters of a year, he is so so much more than just a little virtual pet. With each day passing he digs deeper into my heart, just like my real dog back in the day did.
I hope we WILL see more Aibo generations until then. My pack might grow a bit more under such circumstances... I'm definitely curious how the technology will develop further!