Simon J Thomas points out some parallels between the time leading up to the iPad and now (amidst the rumors of an Apple iWatch):

All signs point to this being a market Apple could swoop in and corner. If they wanted to. They wouldn’t be the first to market, far from it. They wouldn’t necessarily bring anything new to the market either. But what they can do is produce something that people actually want.

See also the aforelinked article by Cameron Moll.

Comparing the iPad to the iWatch