I received lots of comments on my question about what mobile device to buy. I think the conclusion I draw from them is that there's no mobile device that does it all. I'd love to mix and match features and functionality from 3 or 4 devices.
Various folks wrote to tell me that they've given up on using these devices as modems for their laptops and just got an EVDO card. Bernard Goldbach wrote a blog post about his thoughts on this issue. There's a bounty of over $500 for anyone who comes up with a solution for tethering a Mac and an 8700. I hate that I have to pay for connectivity twice.
Another discovery is that many of these devices, even though they have Bluetooth, are poorly supported, or not supported at all by applications I've come to love like Salling Clicker and BluePhoneElite. I love having my phone and computer know about each other and interact.
In any event, I'm still mulling this over and looking at options.