"Because IT requires it" is hardly an enduring and sustainable business model in the age of Consumerization.
From the article:
[N]ot everyone agrees that RIM’s situation is as dire as it appears on first glance, and indeed some people prefer BlackBerrys. After all, the company has 70 million subscribers. To get a sense of what RIM’s appeal is in the iPhone and Android age, we decided to talk to some users and an enterprise smartphone management vendor that handles mobile deployments of all types. Some of Ars’ Twitter followers told us they only use BlackBerrys because their employers won’t allow other devices, and blamed corporate “inertia.” But it’s also true that some people just prefer the BlackBerry form factor, BlackBerry Messenger is well-liked, and RIM is still ahead of the competition in satisfying the unique requirements of highly regulated industries.