Here's the short list:

1. Bluetooth is ONLY good for connecting a headset. That's it.
2. There is no file browser on the device at all. Data must be organized (if at all) in the appropriate application.
3. The camera is a simple application that has ONE button: the shutter. Pictures come out okay on the device, but nothing too fancy on a monitor, especially if it was an attempt at a macro shot.
4. SIM card is damn near impossible to open, if at all. I didn't look into it extensively.
5. Web browser is slow, even over WLAN. Even the simple OneList web app that was created takes around 20 seconds to load over WLAN. You can not highlight, cut, copy, or paste and text from a website, and you can not save any images you find from a website either. The only nice thing about it is the tabbed browsing, which crashed on me when I went to Engadget and YouTube on two tabs. This is the only application that allows you to use the keyboard in landscape mode.
6. The keyboard sucks. It gets slightly better after the iPhone "learns" you, as the employees said, but even then, it's not a device you can use with one hand comfortably, much less without looking.
7. You can only send one picture at a time in an email.
8. No custom ringtones (yet, as we were being told) and the alert tones can not be changed whatsoever.
9. The default ringtones are incredibly lame.
10. The only form of customization outside of a lame default ringtone is the wallpaper, which you'll only see when you need to unlock the device or when you get a phone call.
11. "Picture pinching" or using two fingers to zoom on any content is certainly fun to play with, but not practical whatsoever. This operation depends solely on using the device with two hands.
12. No document editor or native viewer. You can not store documents on the device to be viewed, they can only be viewed as attachments when they're sent to your in an email.
13. Visual voicemail is laggy and reacts about the same way as pushing the fast forward and rewind buttons on traditional voicemail systems. The only advantage is for those that get that many voicemail messages a day that they need to sort them according to priority.
14. NO games. None.
15. No voice dialing.
16. No speed dialing (which can be made up by the "quick list", but getting to that quick list isn't as fast as holding a single key on a real keypad).
17. No video.
18. No MMS.
19. It's still <4GB for $500 and <8GB for $600
20. It only takes around 2 hours to explore every menu without any options for expandability except to scrounge around for new web apps that will load slowly and nowhere near as smoothly as the native apps.

This device looks like it was aimed at the general consumer who has the money to spend on such a flashy device, but it leaves so many basic features behind that it's almost impossible to consider it a success as a mainstream device. It encourages the advanced user to move away from MMS and into email to send images, but leaves out any advanced features advanced users would be accustomed to, and still retains a huge price tag on top of it.

It's certainly pretty and Americans will buy it because of that simple UI, but anyone who's familiar with other operating systems would be appalled. This phone needs to be unlocked and cracked WIDE open to make much better use of the multi-touch system. That, or it needs an immediate update in iTunes to rework every feature.