What I want for my ultimate mobile computing device:
1. Small, lightweight and have physical keyboard
I walk a lot so I want small device that fit comfortably in my backpack (so that's below 7'') and weight less than 1.5(preferrably 1) pound. I'm not all-day mobile warrior so I can live with cramped keyboard but after testing my wife's galaxy s2 touch keyboard I decided I DO NEED a physical keyboard for typing documents/playing games(like nethack, old dosbox compatible games).
2. MS application/IE compatiblity
I need to do business with MS office documents and MS IE only internet banking/payment processing. Libreoffice is not good enough if you have to edit/exchange MS office documents with other business entity(and that stupid and powerful entity is stubborn enough that it want genuine MS office docs only and complain slightest of incompatibility problems)
3. Very low power
10W - It will still need fan or huge heatsink. Moving part/high power is not good for longivity/ruggedness let alone battery life. My estimate is that you'll have to go below 2W to acheive compact & sleek design without fan/huge heatsink - Yes atom Z5XX do that and I have one now.
4. usable graphic core without fsckup.
I need graphic core that supports linux well and play angry bird. PVR core in atom don't support either. Even their xp driver don't support basic opengl well enough.
5. Support basic net tools/secure net connection I feel comfortable
I want to redirect all normal net connection via VPN using my secure home base using openvpn when I connect to untrusted/public wifi. I believe that is reasonably achievable(without heavy source modifying/manually recompliling) with only linux/winxp~7 for now. And I hate OS that don't support basic net tools.
6. Trusted application that I know What it is doing.
I don't want application that does unknown things behind my back(leaking private info for whatever reason or doing net connection I don't want it to do). So I prefer well known/open source apps and become skeptical on many android/google apps.
If you go ultrabook route, you can acheive 2,4,5,6 for now.
If you go atom route, you can achieve 1,2,3,5,6 for now. Currently I've settled for this.
If you go arm based smartphone/pad route, you can achive 1(depends on device),3,4,may be 5 (if you rooted your phone/pad) for now.
With WINRT device, may be you'll be able to achieve 1,2,3,4.
Of course things are changing so somewhere in future may be you could do things with a platform that counldn't do for now(compatibilty/standard compliance got better,intel finally make 2w non-atom processor/drop FSCKING pvr core from atom, better performance to run emulation comfortably, corporation changes their mind about privacy...). So I think it is the race between platforms which acheives the most within reasonable time.