I have to disagree with you on the business market front. Most companies(excluding some obvious examples) use PC's/Netbooks only for doing basic data-entry and specialized enterprise software that usually runs of a browser anyway. Tablets when priced correctly will offer a significantly lower TCO to these companies compared to traditional PCs. Google, tried(unsuccessfully) with the Chromebook to tap into this sentiment, though I think their overall vision was right. If we are going to live with data on servers or cloud, why need a full blown PC. Its the pricing that is the current challenge to all vendors. Once, cheap tablet options come companies will realize that their TCO's will be significantly lowered by adopting these devices.
I should have defined PC more clearly. To me a PC is any device that runs Intel's(or AMD's) X86 Architecture, Is windows based and is non-touch. Touch-based PC's are just an evolution of Tablets. See Lenovo's new Thinkpad Tablet, where for $100 you get a keyboard and it converts to a Touch-Based device running "Android"!!. Microsoft, in their new Touch-Based PC's is going to mainly use ARM processors, which means all the old windows software is not going to work. MS might just invent a new OS and Device for the same, but I guess for marketing purposes is calling these devices "PCs".
I disagree with some of the points in this post. I like Google's hangout feature it is neat for group video chats. I use G+ more to follow than friends. I don't think G+ can beat Facebook on friends feed, however it can beat Twitter for following famous people/tech-writers. Personally, combining the two in Facebook's subscribe feature is a nightmare for anyone having more than 100 friends. Ultimately, G+ will get a niche as Social for their products, but not beat Facebook.