Should I wait for the iPhone? Apple's new phone is beautiful, but it uses Cingular's slower EDGE network and may not be a mainstream choice for businesses.
Will I still need an MP3 player? Probably. Most smartphones have memory cards that max out at two gigs. That's about 500 songs - enough for your commute but not your entire music collection.
How hard is it to switch phones? Transferring contact data, appointments, photos, etc. from one phone to another - even with different brands - is now pretty easy.
Don't I need a corporate IT department to synchronize e-mail, contacts, and calendar between my phone and computer? No. It's easy to do all that wirelessly using free Web services like Yahoo Mail and Google Calendar.