A new industry in jail-breaking PC's is just around the corner probably.
Or a new generation of PCs where Google Chromium sneaks in and takes 50% of the market virtually overnight. Sort of like they did with Android?
How often does someone come in and take 50% of an existing market? More likely is that people invent a new market, duke it out for a while, and eventually a winner (or clear leader, if you will) is born. Microsoft won the desktop market. Google won the search market. Apple won the MP3 player market. Amazon, the e-book reader market. We may still be in the 'duking it out' phase for smartphones, though you could choose to look at it high-end and mid-range (Android's gains are at the expense of the feature phone, not the iPhone). Windows 8 is interesting in that it is trying to use one thing on both tablets and PCs. Windows 8 is obviously a response to the iPad - and a response which considers UX and design far more than anything the Windows group have done for years - but is there a tablet market to come? (Many have said there is no tablet market, there is only an iPad market, and I have an ignored TouchPad somewhere to prove it.) Depending how all-in they go with Metro, the corporate market may have a few years of staying with Windows 7 before moving to some sort of new thing. Could it be a Linux on x86 hardware? Possibly. It could equally be Mac, or web only on any device. You can't run other OSes on the iPad, but that doesn't stop people buying them. Companies will still make hardware with open firmware - though yes, it might cost more, and old computers don't suddenly stop working. Or just go buy a Raspberry Pi :) Craig