I agree with this. I am not sure if I see a compelling reason why Win8 on desktop should take off for businesses. It will be a transitionary version just like how Vista was.
Windows 8 tablets? Same story. Why would I as a consumer want to spend $600 to get a tablet with so many unknowns? What does it provide that the iPad currently does not provide? I keep wanting to find a good set of reasons but I can't. You just know what your $500-600 is getting you when you go to iPad and Android. Unless MS lowers the price point to $150-200 it will be a tough sell in my opinion.
The software side of things are very different though. Being a .NET developer for years (after coming from UNIX) I find myself using Java and open source languages more and more often.
If you are an ISV/entrepreneur I am just not sure if it is a good idea to bet the future of your organization on Microsoft's mercy. They keep changing languages/platforms like they change clothes lately.
Nonetheless, the next three-four years will be fun to watch.