Gizmodo has a hands-on with the Sidekick 3, which apparently will be unleashed on T-Mobile customers in 8 days. Perhaps it's just the Gizmodo reviewer's lack of familiarity with the SK platform at work, but I find this piece somewhat discouraging. Yes, there's Bluetooth, an audio player and a slightly better camera, but large parts of this review read exactly like the author is talking about the Sidekick 2:

Little notifier icons in the top right corner inform you when you have a message in IM, mail, or SMS/MMS. Messages appear in a little bubble for a moment before disappearing, so you can assess the value of emails and messages before reading. There is an airplane mode that turns off the wireless and basically lets you browse your mail like a madman but little else.

The trackball is a real winner. It lights up with all the colors of the rainbow—actually about 10...

The battery lasted one full day....

Voice quality was fine and reception as about as good as can be expected. One pet peeve—it would lose its GPRS connection and only a full reboot would get it back...

Ah well. I think the GPRS speeds have been bumped up, too. If that's the case, it's probably enough of a reason to upgrade (the Bluetooth is the main attraction for me). Still, I was hoping for better battery life... maybe even... GPS? I know, I know, I'm asking too much.