To me, so far he looks like a generational talent. In juniors as a 16 and 17 year old, he put up points like no one in the history of the CHL (especially in relation to his competition) and won the CHL player of the year in both years he played (something else that has never been done). Gretzky outpointed him at 16 (but still didn't win his league's scoring title, probably mostly because the draft age was 20 at the time) and played in the WHA at 17. You could potentially argue that Lindros was a better junior player than him (he was definitely a better prospect at the same age becasue of his size), but none of Canada's other so called generational talents since Lindros can compare to him at a junior level (at least I don't see how you can logically rank anyone over him). Lindros is 14 years older than Crosby, which is a generation in hockey.
At the NHL level, I don't think any 18 year old rookie has led his team in points since Yzerman 22 years ago, and it looks like Crosby has more than a good chance of doing that this year, even surrounded by a cast of name players. Maybe he won't improve terribly much and be the one and only dominant offensive player in the NHL, but from everything he's shown so far in his career, he is a generational talent. At least he's shown for me that I can't say he's not a generational talent at this point.
At the same stage of their career as Crosby, who would you consider, or who have you considered a generational talent? Or do you wait until they've reached a dominating status before you call them a generational talent (like how Gretzky, Lemieux, and Jagr dominated the Art Ross)? If you do wait, I agree that you should wait, so you don't annoint guys like Spezza or Schremp generational talents at 14, or guys like Cleary and Samsonov generational talents at 15, but at 18, Crosby is producing and playing in the NHL like very, very few before him.