From a corporate perspective RIM is going nowhere.
If MS actually gets their shit together with a half decent activesync management setup then RIM needs to worry.
Let's not even talk about apple's total failure in the business segment as another other than a toy.
You must not have used Exchange 2010. It's ActiveSync Autodiscover is wonderfully simple. Plug in email address and password, and it configures the rest for you. Can't be any simpler than that.
That said, I believe RIM's major downfall in the enterprise market is their requirement that you use BES. BES is a piece of shit middleware that needlessly complicates things. It's buggy as all hell and doesn't work half the time. And, until the most recent version, was heinously expensive. They made a large step forward when they made the latest version free for up to 2000 users. However, unless in the next version of their software they offer native ActiveSync support, I seriously doubt that many people will be considering them.
Our customers are dropping Blackberry in droves because of issues with BES. In the more tech-savvy places (or the places that listen to our recommendations), they're getting Androids. In the places that knee-jerk or don't listen to our recommendations, they're getting iPhones. We only have a couple places with WM phones anymore. I just hope that Google fixes the ActiveSync Autodiscover in their next version of Android.
Also, I believe that RIM pricing their tablet at the same level as the iPad is a bad idea. Apple products command a premium because of the image associated with Apple. Despite that, it's bound to be an inferior product anyway. And they're incredibly late to the game. I see it flopping, for the most part.