'Fun' is relative.
Two days? In a corporate setting, with common tools, replacement systems are configured before the user gets them in under an hour. Figure an hour at the user's desk to physically install it and move any existing data. If you're just upgrading the user's OS on the same system, that can often be pushed to the computer overnight, resulting almost no downtime for the user. My computer-illiterate users coming from XP can be productive in W7 after a ten minute summary of the changes they'll notice most.
I've never considered an operating system to be 'fun'. I've found nothing fun about it on a non-touch desktop yet, but fun is relative. What do you find fun? The touch capabilities can be found on other systems, and are more a function of the hardware and drivers than the OS. From a workplace viewpoint, I haven't found the default Metro apps to provide any useful features.
