This is something I've wanted for a few years now (even before the Edge). But the more I think about it, the less sense it makes. To explain, let's examine a couple variations.

First, you have your phone which connects to a dock, which lets your keyboard and monitor connect to the phone. Now, replace the dock with a full computer, but uses the phone for storage. If you had these two systems side-by-side, could you tell which one you were using?

I guess that there is something to having your state be saved, so you can take your phone off the cradle, connect it to another device, and resume all your open apps. But the same could be done if the cradle is a full computer, and undocking the phone does a suspend-to-disk (remember the phone is the storage device). You'd just have to have that action integrated into the undock button. But overall, I think I would be better served by having the phone be the storage device for my desktop computing environment, instead of also being the CPU, GPU, storage, RAM, network, usb, and everything else.