That's pretty open-ended, so much so that any analysis is meaningless. The iPhone has been out for 5 years now. is that not long enough for Apple to have "devalued" in the manner you speak? If so, then what is a long enough time? 10 years? 20?
Personally, I think there's good in having more iOS devices in user's hands. I don't want a status symbol, I want something that works, and that allows me to work with other people. Having iOS become more and more common means a greater deal of support by developers and vendors.
Putting it another way: if only 20,000 or so people had iPhones, then sure it would be a great, rare status symbol to have. But I doubt there would be nearly as many apps out there for it, diminishing the usefulness of the devices. In that regard, I'd say that to me, more people using iPads and iPhones makes it (and Apple) more valuable, more iconic, and more recognizable.
This is why market analysts continue to fret over how much market share Apple, Android and other platforms have. Investors want more people using the product. And RIM, for instance, hasn't exactly improved in "value" now that their phones have become less ubiquitous.