We made the plunge and got 2 iPhones.   One for me and one for Holli.   First off, I have to admit, I LOVE IT.   Holli loves it too.  Our Verizon contract was up, so it was a clean switch without any early termination fees.  So far the AT&T service has been great and I'm definitely used to the virtual keyboard already.

Things I Don't Like:

• No way to sort Exchange email.  
• That's about it :)

Things I Like:

• The email interface is great.
• The app store rocks.  So many awesome apps you can install.  Some apps I'm using:
  • Facebook - I have my facebook status synching with Twitter now.
  • Pandora Radio - free streaming music piped through the iPhone
  • LifeChurch.tv YouVersion Bible - very nice interface
  • Evernote - tracks my notes and voice notes and integrates with a web version
• The Google Reader has an awesome iPhone interface.
• Love the GPS and maps
• The web browser is great, so much better than the IE browser on my old Treo.   Although, I can't stand the Safari browser on a PC.

Holli is even using her phone to check emails.  I'm so proud.