My company has the infrastructure to support the BlackBerry from RIM allowing field personnel to access their email and a few apps as they spend most of their days away from a traditional office and computer.
When the iPhone hit the market and more and more employees started buying them (including influential managers and execs), there was a critical mass of demand and pressure on our IT department to support the iPhone. IT caved in and now we support BlackBerry and iPhone.
The folks who were accustomed to their BlackBerrys are still addicted to them but at my company most new smartphone users choose iPhone.
Apple is investing heavily to make iPhone more suitable for corporate email and apps.
