After reading over the pro-and-con debate on this new development's usefulness, we managed to get our hands on one of these just-announced mice. Our initial impressions are that the mouse itself is a bit bulky for a laptop accessory, and that we've never seen so much extra stuff packed in with a mouse.
Inside the package, we found a fairly standard-looking two-button mouse (there's also a tiny application-switching button below the scroll wheel that requires installing Logitech's custom mouse software), a slim 2.4GHz USB receiver, a USB extension cable dock for the receiver (if your preferred USB port is hard to access, we suppose), a pair of AA batteries, a tiny silver docking attachment, and a surprisingly nice small metal case that contained a second docking attachment (in black) and a plastic tool for removing the docking attachments.
The two attachments have an adhesive backing, and are meant to be used only once, so if you switch to another laptop, or get tired of having the dock on the back of your lid, you have to wrench it off with the included tool and throw it away.
We liked the tiny USB receiver--it sticks out from the USB port just 8mm, and we think everyone should adopt that as their USB mouse standard. We also liked Logitech's purported 18 months of battery life from just two AA batteries.
Attaching the dock itself was painless, and the mouse clipped on easily and seemed fairly secure once attached. Our only problem was that the mouse slides up onto the dock (rather than down on it) and putting the whole contraption into a laptop bag, we could easily see the mouse getting knocked off.