As has been mentioned the more units Apple sell the less cool the brand will become, thats just the nature of the world.
For example when blackberries first came about all the managers and directors had one to show off their status, then when everyone and their dog started getting one the managers moved onto iPhones to prove their uberness. In my company now a lot of lower end staff are starting to get iPhones as the carriers are offering better deals, so suddenly the iPhone isn't quite as impressive anymore.
I also remember once having a discussion with a guy who e-mailed my work complaining that a website wouldn't work on safari properly (this was about 5 years ago to be fair), and he started spouting off about how secure it was and people like macs because they're safer than windows.
Now i personally believe that this is going to end very soon, the more macs are sold the more attractive the platform becomes to criminals to exploit, the pwn2own contest every year has shown that there are a lot of holes in safari that can be exploited so it's no more secure than W7 with IE (actually safari has usually been the first to fall). Once those viruses hit apple loses a lot of credibility as they've been trumping that card against MS for years, and i think it'll hurt their PR and 'coolness' quite a bit.