Some more thoughts…
Safari understands RSS, using the “secret” reader.mac.com address. Odd, but I guess that’s how Apple will keep network use down. It doesn’t auto-recognize RSS feeds like Safari Mac does (with the RSS icon in the URL bar). You need to find an RSS link, click on it, then you can bookmark as appropriate. They should show the RSS icon as Safari Mac does.
You can have multiple email accounts at the same time, which is nice. But it isn’t handled particularly well. When sending a message, the new message screen doesn’t tell you what mailbox you are in (you need to check before clicking the new message icon). This should carry forward.
Critically (in my opinion) – there should be separate auto-checking and notification preferences for each account. I have one account I’d like to check as often as possible. I have others which are fine every hour or two, and don’t even need notifications.
The headphone jack is strange. Others have written about this – it’s quite recessed. My over-the-ear noise-reduction headphones don’t fit. I’m sure there will be adapters available, but that’s another thing to remember. I’m sure there’s a reason for the design.
The camera’s white balance is…strange.
Overall (just so it doesn’t sound like I’m whining) I really like the iPhone. The things I don’t like are small in nature, and also (other than the headphone jack) software-related. So I shall endeavor to pester Apple as need be for updates.
If anyone is curious, I’m using the Speck Toughskin case, and Power Support Crystal Film screen protector. Both bought at the Apple Store at time of iPhone purchase. The case is nice. Not sure how I like the belt clip part of it, that’s to be determined. The screen protector is perfect; can’t even tell it’s there. No impact whatsoever on appearance or touchscreen performance.
Oh, a major iTunes issue. You can’t manually drag songs/videos/whatever into the iPhone, like you can with any other iPod. You have to sync everything, or specific playlists. I don’t like this at all. I’ve always managed my iPods manually, and really miss that ability. Hopefully it’ll come back.