IPads? are they here to stay or a passing fad? I mean: will they be used beyond 5-7 years?

Can I connect one to a printer? a scanner? Does the 4G or wireless service work everywhere, including inside heavily bricked buildings? Why purchase an iPad rather than a laptop with a mobile wireless connection? Apps are nice and helpful and there are plenty out there, but bost apps are frivolous in my opinion so purchasing an iPad so it can tell me what color tie I should wear is rather senseless.