I am planning when I get my XPS 13 to run Windows 8 in a VirtualBox. This should be no problem due to the 8GB RAM ...

Thanks, but surely someone has already changed from Ubunto to Win 7/8?

I would actually not expect it, as this system is meant for Ubuntu. If you want that, you could buy the regular XPS 13...

I think in fact that if you install Windows, you should be able to use the drivers Dell supplies for the regular edition, as it is most probably the same hardware

Yes, you can. I have just installed Windows 8 for testing my Wi-Fi card (en.community.dell.com/.../20429073.aspx) and this is the procedure I followed:

1) Download a Ubuntu live cd and put it on a bootable pendrive (drive 1).

2) Put the Windows 8 image on a bootable pendrive (drive 2).

3) Boot from drive 1.

4) Use gParted to resize partitions and create a logical ntfs partition in the already existing extended partition (minimum 25GB).

5) Now boot from drive 2 and install Windows on the ntfs partition you created.

6) After Windows 8 has been installed and configured, reboot with the live distro (drive 1) and follow this guide: help.ubuntu.com/.../Boot-Repair. Be sure you install grub on sda, and not only sda3, or Windows will boot first.

Thanks very much Frapontillo for the detailed advice.