The only negatives I've seen so far regarding the iPhone are that it takes time to learn to trust the on-screen keyboard and that the headphone socket is recessed, meaning some third-party headphone jacks won't fit in.
The keyboard I can understand and it's a temporary problem, until you get used to it.
However, whose stupid, stupid, stupid idea was it to recess that socket? When I first read that the iPhone would have a standard 3.5mm headphone socket, I was thankful that they hadn't used a 2.5mm socket like 99% of mobile phone manufacturers.
Well, Jonny Ive had better rethink things before the Australian release, because if my $230 Etymotic ER6i headphones don't fit in there, Stevie won't be getting any of my hard-earned cash.
If I was a skeptic, I'd suggest this is just a way to make a few more bucks from some percentage of users, by selling them a $20 adapter. However, I would think the discerning types who want to use a better set of headphones won't want the hassle of that extra piece of plastic.
Update: According to Engadget, my ER6i headphones do fit. Yeah! Still, it's bad news for many other third-party headphone owners.