What can be easier than sticking a kernel.img onto a fat32 formated sd card ?.

And ARM use less battery power than x86.

one down fall is memory with arm devices.
even cell phones have this problem..

there not up-gradable..

plus why could they not make a x86 pc boot from a sd card..
now bios supports usb booting.. .just add SD and make it boot
different formatted disks types..

M$ x-box arm:
http://www.xbitlabs.com/news/multimedia/display/20111107232643_Microsoft_Xbox_Loop_to_Feature_ARM_Processor_Windows_9_Core_Report.html

there is plenty of competition-
Mac
M$
Android
Linux
...
...

Arm does allow for more portable devices and low power..

This may be why windows 8 is loosing its start menu and starting to look more like a arm device rather than a windows menu

over all arm is cheaper to produce..
...
but for power I would choose a PC..
for portability would choose arm..

I do not think x86 will disappear for some time..

Would be a weird day to walk into an office and see arm computers ..
instead of PC..

yep, it's really sad that android devices cannot be used as live usb boot drive.
i've tested, it don't work.
if this feature comes to be reality, anyone can have his personal OS embeded and boot any pc in the wrold, just by connecting the usb wire at before startup... that's would be very fine.
and better would be to have a full PC compatible smartphone, able to run dos, dexos, windows, linux, etc... and then, have a duplicate of the rom just to provide a second bootable copy of the system for the usb boot on a pc, while the system is still runing on the phone. and have a sort of share zone to work on both... use the phone as a mouse/keyboard for the pc... etc...

edfed,
here, the asus padfone, tablet with phone i guess
not the one like your concept, but roughly 10% maybe.



http://phandroid.com/2012/02/28/asus-padfone-hands-on-phone-tablet-laptop-collide-awesomely-video/

new open source game consel:

OUYA Open Source Home Console:
http://www.youtube.com/watch?v=OfgX032Jbvg&feature=related

I had tried with a blackberry 9000 with a small linux distro installed on a sd card and it worked.
What I needed to do is click YES on the blackberry to activate the SD card while the pc was booting.

Enko,

That's really annoying: I'm physically attaching device to another, then it asks: "Are you sane? The other end of the wire is going to use me!!!"

It's OK for wireless, but unbearable for USB/FireWire/whatever non-ethereal.

It is a simple measure to stop unexpected virus-infected SD cards getting CPU time. Just like the stupidity of Windows autorun being on by default, it is one of the best ways to give unwanted code access to your system.