For those of you who haven't read the other reviews:
The keyboard has been upgraded so that it should no longer have the problem where keys peel off.
The screen is not much different from the Sidekick2.
The whole device is noticeably smaller than the 2. I like this as it fits into the pocket better and is far less awkward to type on than the two.
The voice quality is not bad or great.
The AIM instillation seems solid and you can now toggle back and forth between conversations by tapping the buttons on the side/top of the device.
It has all four of the top IM platforms: Aim, Yahoo, ICQ and MSN. You can run more than one of the IM platforms at once.
It has a removable battery, this is a huge improvement since it will allow those who make heavy use of it to get a second or third battery if needed.
Overall its a decent evolution over the Sidekick2 but not a revolution.