The strongest feature BlackBerry has ever had, I think, are their keyboards, users liked them. I know corporate business users got use to them and I suspect they don’t want to go to a touchscreen only model.
If you’re an existing BlackBerry user that types work emails from their phone what do you switch too?
iPhone, with a touchscreen, doubt they’ll like it. Sure some people are fast with touchscreens but I think a physical keyboard is still going to be quicker especially for non-newbies. Newbies might have a fighting chance at being better with a touch screen but I don’t know.
Android or WP7? I suspect most carriers carry one or two with physical keyboards. No not a lot of choices, that’s not a good thing.