ET3D: Many Android apps are written in Java and are usable on any Android device regardless of CPU type, and this includes BlueStacks (which lets you run Android apps on any PC). Besides, I already have an Android tablet.
And I'm not sure why you're laughing about x86 in mobile. I'm sure it will become a lot more common, even for Android. As for a Windows tablet, I find the idea of a full PC in a mobile form factor very attractive.
1) Its not same Java as you use on PC, they not binary compatible.
2) CPU agnostic software is ONLY one who dont use NDK. ALL games which use at least a bit of hardware acceleration - uses NDK, so its not CPU agnostic, and as you can guess, 99.9% uses NDK
2a) Textures format - GPU used in Android devices use something like 4 known textures formats. Non is compatible with GPU used on desktop or x86 oriented hardware. But thats smallest problem, actually.
3) Bluestack is nothing more then seamless integration of android app which running in special stripped down version of android which in turn is running in virtual machine. So, this is either slow and CPU\RAM hog OR need full fledged visualization support in host CPU. I kinda not sure that cheap and low-power Atom have necessary support for it.
4) Atom processor...well, main problem of x86 is powerusage. They just never was developed for being energy effective. ARM in turn have much better performance\energy use ratio. MIPS was said to have even better performance ratio, but its totally failed to gain any traction in Android hardware due same thing - NDK and big compatibility problems.
Intel, ofc, tried a lot to make Atoms more energy effective, but ways they had to use is - making them less powerful and\or stripping down functions to make them less complex, because they cannot improve them radically without radical changes which they make them incompatible and by that ruin whole idea.
5) And in the very end, idea of "tablet PC with windows" is soo...not new. its like second or third iteration of such devices, there was Windows Tablet before, and UMPC later. Same idea again and again, who know, maybe they implement it right way this time...