I don't think storage is something that is standing in the way for tablets to replace portable computers. If it was, all you need to do is to slap in cloud storage and voila, theoretically unlimited space. Its more to do with productivity and flexibility and these two things can never be fully achieved under walled gardens. Once OS providers start porting their full OS suite to tablets, we might see a good traction. Glad to see Windows and Ubuntu are moving in that direction and hoping others to follow.