Personally, I would love to have a Z sized clamshell device that runs Windows. It would be great for compatibility and running every application my desktops do at work (where we use Windows). However, I don't see many such devices that run WINDOWS, they run CE. The cool thing about the Z is it doesn't run some other OS that looks like Linux, it really runs Linux. I can really run real applications on it, not just applications that look like real ones that were recoded for my OS. Besides, anything that can run XP should be able to easily dual-boot into Linux.
I think what we all really want is for PDA's to become like PC's. Where the hardware is standard, even if it is tightly integrated, so that we can choose our OS and share drivers between devices.
Or maybe we just need PC's to become as small as PDA's, and then the point will be moot.
Personally, i want to see the modular PDA system, where your base component (CPU, etc) is one box, and then you can buy any "interface" device you want. The "brains" would just be a small box that fits in your pocket, or bag, or maybe is part of your cell phone. Since it would have no I/O (just wireless and a small USB port) it would be very small and could be shaped to fit things like a pocket, or even strap to your side, because you never need to get it out. Then you have a display device with maybe an integrated input device, or mayber not that is separate and communicates wirelessly. An open standard, of course, so that multiple vendors could supply these. Eventually you could then use the video in your sunglasses with it, or your cell phone display, or your LCD credit card in your wallet, or all three. You could get a new "brain box" and keep using your existing I/O components.
Of course, it needs to be wide open standards, so we can choose from who we buy our "brain box" from too, and so that we can boot any OS we want onto it.
I really feel like Microsoft sees the PDA as a way to reclaim their stranglehold on a platform. The dsektop is too open for them. They are in the place of having to cater to the hardware that is there, and having to compete with other OS's. Microsoft sees the PDA as an opportunity to have the hardware catering to them, and to elliminate all competition. Just like the carrier locked cell phones, Microsoft likes to see "OS locked" devices, which PDA's are very close to. Like phones, they can be unlocked, but it isn't easy, and certainly isn't something the average consumer even thinks about doing.
I do watch all portable Windows XP platforms with great interest, but so far they are much bulkier than the Z, and the C760 really is about at the absolute limit of being a pocket machine for me. Not to mention that they are all rather expensive.