My iPhone 2.2 hasn't repeated its post-upgrade reboot during phone call, so it again qualifies as an excellent cell phone and a decent iPod .
It's also a lot of fun. The kids love seeing what kind of silly nonsense Google's speech recognition engine produces.
Alas, it's a long way from being ready for business. Apple, frankly, doesn't give a damn.
Business people always stick travel itineraries into calendar item notes. I stick text versions of CVs into Contacts. The iPhone truncates the text display of my itinerary (what hotel?) and my contact note. It doesn't actually truncate the data, only the display.
Right there you know Apple isn't serious.
There's more though. Compare Google Calendar to MobileMe. It's not even close. It's like comparing Rembrandt to paint-by-numbers. The business problem is that Apple will do over-the-air (OTA) sync to MobileMe, but they won't provide a calendar API that would let Google implement OTA to Google Calendar. 
No tasks . No memos/notes. No cut, copy, paste (will never see it at this rate). No background notification management that would enable business friendly spam-managed instant messaging. Contact search on names only.
Corporations and small business may be feeling some pressure to enable iPhone use. Heck, I'd like to use my iPhone on our corporate LAN -- but this is the wrong time to give in. The iPhone is not ready for corporate or small business use.
Wait until Apple is serious.
The (rather dim) bright side of Great Depression 2.0 is that it might concentrate Apple's mind. Maybe they'll decide they need the iPhone to be a great phone, a great toy, and a great business device.
 Navigating within a podcast is much inferior to an iPod and you still can't set the alarm to a playlist. Nice video though!
 I'm watching Neuvasync closely. Getting there ...
 Much as I like Appigo's work, their back end sync to Toodledo has been a mess.
Update 11/24/08: A recent TUAW post referenced this July 2008 list of enterprise shortfalls. I like my list better, but I forgot to mention the persistent lack of support for an external keyboard. It's not just unready for the enterprise, it's unready for work. Period.
Update 1/14/09: The business problems will not be easily resolved.