While relevant, to be fair he meant as the primary method of interacting with and navigating a handheld device, as in needing a stylus to scroll through your email, make calls, etc. This 'pencil' is simply for painting and drawing on a tablet, arguably a different scenario.
Probably that was the reason why Apple did not have the courage to do so, but it is obvious that it creates additional value for some people. Especially designers and illustrators, I think.
He didn't seem to have a vision for tablets replacing pen/paper notebooks. The tech is here and prices are getting low (e.g. dell venue pro 8 with a stylus for ~$400); soon mainstream consumers will go fully digital and trash physical notebooks. Apple still can capture this opportunity, but they need to get past this idea that stylus==bad.
I'd guess the first company to get a 10" tablet with a good notebook application and stylus for under $300 will be the big winner in the classroom for the long run.
- Steve Jobs