From a Tidbits discussion post (emphasis mine):
My wife and I wrote a few weeks ago about our frustration with Apple's iCal features on the iTouch and iPhone. We have 6 calendars that work fantastically on our home and work iMacs, but we are confused looking at the amazing limited version of iCal for iPhone. Can anyone explain to us the limitations Apple was facing that forced them to opt for a version of iCal where you can't make appointments on your different iCal calendars (or view them, for that matter) on the go? Why would anyone using Mac syncing of their iCal calendars even consider the iPhone and iTouch??? We won't be able to get either until this is fixed...
A man after my own heart. I know I'll feel the same pain. This why we need the SDK, so small vendors can provide solutions for power users. Apple can't justify the cost of supporting folks like us.
In a related note I've a post pending on Google's gCal sharing and notification services, and the issues (design and bugs) related to multiple Google Apps and Google Standard identities.