I'll follow up with a longer term test, but right now I can tell you Bluetooth allows for much easier syncing of my PowerBook address book with the Treo, but even more stunning it allows me to use my Sprint service with the PowerBook when WiFi isn't available. It's not blazing fast but a nicer way to email than using the Treo's thumb board. The camera, shown in detail to the right here, takes decent photos but isn't going to replace my Canon yet. Here is a sample photo. In the few days I've had the device I can tell you it's been indispensable. No word on whether this is going to cost more than the 600.
[update]: Yes, this was a very geeky April Fool's joke. I do have the 600 and recommend it to those of you suckered in by this post. Nice sleuthing on the TreoCentral Forums. FWIW, I don't think there will be a Treo 600 successor until late this year.