Pavan Rajam has a thoughtful post on Apple and wearables. Importantly, he reminds us that it's hard to truly imagine what doesn't exist. Heck, sometimes it's hard to truly image the importance of something we are shown.
Just watch the keynote, and pay attention to the audience reaction when Steve Jobs introduces the iPhone. Both the “iPod” and “phone” slides receive uproarious applause, while “internet communicator” gets a relatively tepid response. Ironically, it was the “internet communicator”...that went on to define the modern computing era.