I treated myself to a Samsung Galaxy Tab 2 for Christmas this year (7 inch screen). As I get used to it the desktop and laptop are used much less.
I tried Android a few years ago and didn't like it, now it seems to have matured into a useable os. I'm aware that the android phones have the same capability however my middle aged eyes and chubby fingers like the bigger screen.
I like the fact that it really didn't come with much for documentation and really doesn't need any. Within a few days I figured out how to navigate around the screens and install apps. It won't replace my desktop for business use however for everything else like web surfing , email etc. it will soon be my computer of choice.
Microsoft is pushing Windows 8 on both the phone and pad fronts, probably in a long term bid to stay alive due to what appears to be a future collapse of the traditional PC/laptop market.
iPad was certainly the one that created the demand for tablets, however it's facing less expensive and more powerful machines running Android.
My thought is that the pc's except in a few businesses will soon be replaced with i phone and android phones, your comments are welcome on this...