[PennylessZ28]

I like these reasons from Paul Thurrott's supersite about why it's crap.

Obvious problems with the iPhone

Given that I don't have an iPhone sitting here (yet), and didn't until recently even expect to get one, I'm still a bit mixed on it overall. The product looks decent, even excellent. It has the expected Apple design touches and UI innovations. But there are some problems. Here are the issues that I think are relevant, as I now understand them. Things may change as the iPhone's June 29 release date approach, and of course Apple updates its products regularly, so expect even more changes down the road.
Design. The iPhone is better looking than any smart phone, period. It's also bigger and heavier than most smart phone users would prefer, so it's a mixed bag overall. And what about that touch screen? Will it scratch easily in your pocket, like an iPod, even with its newly-announced glass screen? Stay tuned.
Keyboard. The iPhone does not include a real hardware-based keyboard, which makes it a non-starter for the two most important smart phone markets: business users and those who regularly send text messages. It doesn't matter how good Apple's virtual keyboard is: Without a real keyboard, there is no tactile feedback, and thus you cannot type easily on it without watching the virtual keys. Apple would have been better served by providing the device with a slide-out or even an add-on keyboard. This is a key (ahem) area where Apple has completely misread the market, and the company is only making it worse by pretending that it has invented a new market, implying that the old rules simply do not apply anymore. Hogwash.
Network. The iPhone will only work with AT&T's inferior data network, which has been disparagingly referred to as a "2.5G" system, compared to superior 3G systems like the Verizon EV-DO network I happen to use. (On the flip-side, the iPhone does support Wi-Fi natively, which will come in handy, more so in the coming months and years.) Switching mobile phone providers is expensive, and limiting the iPhone to just AT&T will make the device artificially less relevant than it could be. And if you're in Europe, you're just plain out of luck, for now: Apple has not (yet) announced its European mobile phone service partner yet.
Compatibility. While the iPhone will work just fine with all POP3 email accounts, and will work in superior fashion with the natively-designed Gmail and Yahoo Mail systems, it will not work with most corporate email systems, which, in tandem with the lack of a real keyboard, makes the iPhone a non-event in the business world.
Internet. While my Motorola Q I use can browse the Web, and do so via the superior EV-DO network, most Web sites are not designed for the device's small screen, and finding sites that do work natively is difficult and frustrating. The iPhone, by contrast, offers a "true" Web experience because it has taken a desktop PC-based browser, Safari, and jammed it into a mobile device with a nice, large widescreen display. However, Safari is also an iPhone weakness as so few sites are designed for this niche browser. Why, oh why, couldn't Apple have just gone with the superior Firefox browser? That would have made this category a slam dunk.
Battery life. Apple now claims that the iPhone gets 8 hours of battery life for phone calls, which any cell phone user will immediately peg as a ludicrous claim. However, Apple had previously claimed just 5 hours, so something positive has happened here. A user-removable battery would make all the difference in the world, of course.
Storage. The iPhone comes with just 4 GB or 8 GB of storage, depending on the model, which will limit the device's ability to store your entire media collection. Movies, which should look wonderful on the iPhone's widescreen display, are particularly problematic. A typical 2 hour movies purchased from the iTunes Store weighs in at around 1.5 GB. Worse still, this kind of content will rapidly sap battery life.
Availability. If you do want an iPhone, be prepared for disappointment in the short term. You can only order the device through certain non-franchised AT&T retail stores, Apple retail stores, and, presumably, Apple's online store. I say presumably because, of this writing, you can't actually pre-order an iPhone anywhere, get on a waiting list, or even learn how the sales will be handled. Obviously, you'll need to sign a two-year commitment with AT&T, standard practice in the US cell phone market. The details, alas, are lacking. See below for more information. Also, consider this: If you purchase an iPhone and decide you don't want it, AT&T will charge your $175 to get out of the contract.
Pricing. The iPhone is expensive. Really expensive. While I was able to snag my Q for just $100 (or free, after a $100 mail-in rebate), the iPhone will cost $500 or $600 depending on which model you get, in addition to whatever monthly fees you pay through AT&T. This places the iPhone at the absolutely upper echelons of the smart phone market. When you combine this fact with the availability and functionality issues noted above, you can see some reality setting in: Yes, the iPhone will be successful. It is most definitely, however, not a good buy for most phone users.

Here's what I'd like to add to what he said, he didn't mention how much you'll pay to get out of the contract with your current provider. Do you people already have AT&T ? You'll get charged close to $200 dollars by most providers to drop your service.