One of the troubling things I noticed last summer while writing my lengthy iPhone review was that calendar sync didn't work. I tried to get this going in various ways, eventually to the point of using different versions of Office (2003 and 2007) and even different versions of Windows (XP and Vista). I documented this work in three blog posts (and, later, in my iPhone review):
iPhone synching woes
iPhone synching woes, Part 2
iPhone synching woes, Part 3
My conclusion was that iPhone calendar sync with Outlook (your only calendar sync choice on Windows, incidentally) was horribly broken. (Fun fact: It works fine on all non-touch iPods.) I was curious why the New York Times and Wall Street Journal type reviewers never picked up on that, but then I'm sure those guys were holding hands with Apple and using Macs for their reviews. You know, like a good 10 percent of iPhone users.
Anyway. It seems that Apple may have finally picked up on this issue in a support document hilariously titled, iPhone and iPod touch: Some Outlook calendar events might not sync. I'd like to briefly note that I complained about these issues last July. Apple's answer is to upgrade to iTunes 7.5, which shipped in November. It's now January. Geesh.
The issue here, of course, is the same as always: Apple only supports a single calendar sync point on Windows. It's a program not everyone has. It works fine with the iPod. It doesn't with the iPhone.
I'll need to fresh install everything before I'll know if this really solves the problems I've always had--still have, in fact--with the iPhone and Outlook. I'm not overly positive they've really fixed anything.