That's not quite true. The BB is a secure smart-ish-phone which makes it ideal for corporate/government use. It's locked down and encrypted.
Don't get on your platform high horse or anything, something happening too often here (get off my lawn) but ...
Android isn't secure at all. Until Android phones start coming with hardware based encryption we can't use them, it basically rules them out at the first stage. People are pushing to use Android but it is a no go right now. Same for Windows Phone 7, no hardware encryption = no use, although no-one is pushing for WP7.
We're slowly moving to the iPhone 4 through Exchange and a MDM, people want to use the iPhone, we can configure it just as strongly as the BB and it has AES 256 hardware encryption. It's a win-win.