...which may well happen soon.
You are correct. Nothing definitive was said. But just because Jobs said "we think" doesn't mean they don't have plans. I think it's logical that it means Apple notebooks will take a sleeker form and that they will be lighter. What else might the statement mean? That notebooks will all be named MacBook Air? That they will all have 11" and 13" screens? Not likely.
I agree with you that Apple isn't going to be able to put a processor like the quad core i7 into the current MacBook Air case. But I bet in the next couple of years, they're going to try. And that by the end of 2012 all MacBooks including the high end models will be much thinner and lighter. And that they'll all lose the optical drive and spinning hard drive. After all, isn't the company called Apple Thin, Inc?