3. Windows applications have to catch up - The software industry has a lot of learning and then a lot of work to do. There will therefore be a big gap in time between Windows 8 being released for sale and software being properly developed for Windows 8's new capabilities. There is a whole new world of Metro for software manufacturers to learn. We will all have to implement Metro-based apps or portions of our apps properly into our products. Until Windows applications get a chance to mature on Metro though, it could be very hit-and-miss in terms of the overuse and misuse of Metro, which could cause potential reliability and productivity issues. ISVs have had a heck of a time getting updated to the Vista/7 platform. The good news is that those apps should run fine on Windows 8, however they will be conventional Windows desktop only and not Metro-enabled. That being the case, why deploy Windows 8?
4. "Dear Helpdesk, how do I turn off my computer?" - User training and acceptance is a massive consideration. I only listed it fourth because if you don't have a device to install an OS, stable drivers to run it properly, and apps to run on the OS, you wouldn't put it in front of people. Unlike the move from Windows 95 to XP to Vista to 7, Windows 8 is not just a different looking start menu: there is no start menu. You no longer access the start menu to shut down. In fact, there is no default shut down option displayed on the UI when the user is logged in. These seemingly very small things can be a huge disruption for even tech savvy end users. The better bet is to let users educate themselves through a few years of use on their own at home and then capitalize on this user-funded training to introduce the device at work.
5. Consumerization security, and the network edge - On the surface Windows 8 looks and behaves like a consumer product and you better believe the early success of Windows 8 will be with consumers. Everyone has taken their iPads to work and Microsoft expects you to do the same with a very capable Windows 8 slate device. This is tricky because individuals' decision to work from a Windows 8 slate is out of a CIO's control. The upside is that since it is a Windows device, it is much more manageable than non-Windows devices. At a minimum, any consumerization or de-perimeterization initiatives need to be driven by carefully conceived IT policy.
6. Tick-tock but not of the clock - There are releases of Windows that overhaul the entire code base (the so-called "tick" such as Windows 95 and Windows Vista) and there are releases that build off of or extend an existing core code base (the "tock" like Windows XP and Windows 7). Technically, Windows 8 is a tick release, which most organizations wait until at least the first Service Pack to implement, if they implement it at all.