The thing is that to override the Apple Effect, other manufacturers are going to have to come out with a totally killer smartphone. Having seen a couple of those which were forthcoming later this year I don't see that happening. Even if you get pretty close, if you're not definitively outperforming the iPhone I would imagine the market will ignore it.
(Lack of) PDF mentions is something I also picked up on as well, but if rich email is supported, I suppose there's no reason to doubt at this stage that the iPhone will be unable to open such files.
I'm definitely an 'enterprise type' user and usually, all I do and would want to do on a phone is to read and send emails, look up my contacts and calendar, and apart from that amuse myself. I believe it's limited vertical and nerd markets who wants the kitchen sink. I think the featureset is perfect for the mobile regular professional.
Depending on the syncing functions with Windows (and I doubt Apple will ignore that side) it does seem like the perfect phone for me with one major exception.
One thing I definitely didn't see is push contacts and push calendar from Exchange or any mention of Apple technologies in this regard in combination with Leopard Server. If you like me have an assistant who updates your calendar and contacts into a central Exchange Server, then you need your contacts and calendar pushed out to you as well. While I don't doubt that the iPhone could do it, I notice they didn't make any announcements about their own technology or any tie-ups in that regard. RIM certainly won't partner, and I doubt Good would now that they've been taken over by Motorola. That would be a killer step for the larger small business.