Microsoft have said that they are supporting upgrades from XP to windows 7 but to the rest of us that means they are not :( Although the redmond giant will be selling upgrade media it won't be doing any upgrade in any sense of the word previously encountered. Users keen to upgrade (that is users forced to upgrade due to XP support being phased out and Vista being generally acknowledged as being worse than pen and paper) will find they can't keep their program installations like an upgrade usually allows but will be forced to re-install everything.
The user data will of course be transferred with the latest incarnation of the 'files and settings transfer wizard' but the process will be much more drawn out than a real upgrade install.
Deep Joy