Hey, great findings!
So far I know, the Portable Workspace Creator only supports Enterprise edition and requires 16GB minimum space.
It is a great news that the bootable USB stack is enabled by default, but will they disable or remove it from other editions (other than Ultimate and Enterprise) in the final release?
Any evidence to support that statement?
Windows has always installed only the drivers you needed for your system to work correctly. In Windows Vista and 7, they improved though, starting with AHCI and non-AHCI drivers...in Vista and 7, you can tell Windows you're about to change it by running Microsoft Fix it 50470 or by modifying a couple keys in the registry. Then you reboot into BIOS and switch to AHCI or switch from AHCI, boot Windows, and it knows to try another driver instead of BSODing...
This is only one very specific example...but according to the Microsoft support article, it explains it perfectly "During the Windows 7 or Windows Vista installation process, any unused storage drivers are disabled. This behavior speeds up the operating system's startup process. When you change the boot drive to a driver that has been disabled, you must enable the new driver before you change the hardware configuration."
But in Windows XP, you couldn't do this, you had to actually go out and install the AHCI driver and all. It was a longer process. To do what exactly? Avoid a BSOD.
Point is...Windows has always been designed to boot very quick and be optimized for the PC it runs on. It is not prepared for vastly different hardware configurations. When you get a new motherboard, any OEM product key you had won't work anymore...and you run the risk ..."will Windows boot or fail?"
Where's my evidence on the switching-to-AMD issue? Well I always ran Windows 7 on USB using this PWBoot patch and then ran it on AMD machines, and it would BSOD or simply get into a reboot-loop...there were not enough drivers for Windows to successfully boot and connect to the network so it could download and install drivers from Windows Update.
But Windows Embedded Standard 7 doesn't do that when you choose the bootable USB stack, it's much more reliable, because the installation prepares for a USB-aware configuration. How does it work? Windows 8 inherits most of this from Windows Embedded Standard 7, adding on USB 3.0 functionality and refining the entire experience. But what has Microsoft said when they demoed?
They clearly pointed out that it knows to have a select amount of drivers on the USB install of Windows 8 so that if you're on Intel or AMD, or something completely different but Windows compatible, it'll be able to fully boot up the system to the point where it'll be able to connect to Windows Update and install the rest of the drivers. Unlike how currently Windows 7 will simply install drivers for only your system, and not carry over any other drivers for other CPU architectures simply because it wouldn't make sense to do that.
It all comes down to the fact this is an unsupported scenario, and Windows 8/Windows Embedded Standard 7 actually do support this scenario and are optimized for it by either the installation wizard (Windows Embedded Standard 7's way) or on the first boot-up detecting that it runs off USB (Windows 8's way).
Hope it's not too much for you to read. It's definitely interesting stuff though.