"Pushing new releases on a quarterly basis is what Nokia - and many of its rivals - have been doing for the past decade" - Oh for god's sake, when Nokia started doing this is when they jumped the shark, though it took Blackberry, the iPhone and Android to hammer the point home.
I remember the days when most people in my peer group, and not just the geeks, could name at least a few model numbers of Nokia phones, which they preferred, and the differentiating factors that led to this choice. Despite these factors, impressive battery life and a very intuitive UI were consistent across the range.
Then Nokia expanded their range massively, but without obviously useful differentiating factors (and in some cases terrible design choices - 3650 anyone?), whilst the battery life decreased and the UI became increasingly fragmented and complicated. This rapid expansion could have been interpreted superficially as a sign of innovation, but then RIM, Apple and Android came along and demonstrated otherwise.