I think the main issue is that people have stopped buying notebook/laptop/netbook computers. Those used to be the big sellers, but now people are buying iPads and Kindle HD's or my favorite Samsung Galaxy Notes.
What will be interesting to see is if Windows 8 Pro tabs catch on. They are the best of both worlds. Run all the same apps from both Windows PC and Windows Mobile. Play Angry Birds and Diablo 3. I want one even though I don't need it.
Unfortunately I think it's going to be a slow burn for MS. Too many people are locked into their iOS or Android app store purchases. MS was late to the party and even though they came with the better product people are still happy with their limited use tablets and have been convinced yet that they need more.
I think business will change this. Tablets are replacing computers in businesses around the world, but businesses still want to use MS Word, Excel, Powerpoint, etc. Windows 8 gives you both a tablet and a work computer. At your desk you type a report from a dock and a real keyboard and mouse with a larger desk monitor. At lunch play some Cut the Rope with the touch interface. Away from work you answer emails with a fold out keyboard or teleconference from vacation.
Once people figure out that they do in fact need more than an Angry Birds player with Twitter support I think Windows 8 tablets will start to fly off shelves.
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