Across the corporate landscape, folks are asking if they can turn in their Blackberries and Treos for iPhones and they??e not getting a definitive ??es.?Apple kind of says “yes,” but even after Steve Jobs’ keynote at the annual Apple developers conference, there are lots of questions. Most of these have to do with connecting to Microsoft Exchange with the server behind a firewall. I can’t pretend to understand all the software issues involved, including Apple allowing third party developers to write software for the iPhone.