Coverage: Will Nextel be the BlackBerry provider? I can only speak to Verizon and T-Mobile. With Verizon, they have broad CDMA (analog) for voice, and "1X" data coverage, which is more limited. They are not getting the latest handsets from RIM though.
Our T-Mobile coverage is more spotty, since it's all-digital GPRS (voice and data) but they have the 7100t available.
I don't understand rolling out this many BlackBerry units if you're not going to use them for corporate Outlook e-mail. By default messages are triple-DES encrypted, and policies for passwords on the handhelds can be applied. Lost handhelds can be disabled. Here's an article on BlackBerry use in government:
http://www.rim.net/news/press/2004/p..._2004-01.shtml
My users report productivity gains of an hour a day...because they can convert previously wasted time (riding in a cab, waiting for plane, meal, etc.) into processing through their e-mails.