Cost probably has something to do with it
Back in 2008 (Aug) I bought a Dell Vostro 1510 (dual core, 17" 1900x1440, 2GB RAM, 250GB HD) for £360. You can't even get the spec now and the closest is over £500. We've had a massive currency devaluation making imports more expensive but not double the price. So it seems there's some gouging going on and I don't want to play. Maybe others feel the same way. So that's domestic.
Also, my business has reduced it's purchase of kit because we now use so many more Amazon EC2 instances. Much better having Amazon look after hardware/OSs installs and maintenance than us. Maybe this type of behavior is fairly common and so reducing the need for hardware by businesses.
BTW I don't get foxyshadis's point about tablets. I bought an Iconia tablet last year (10.1", 1024x768, 1.2Ghz, Android 3.0). Everyone else was buy a tablet so the must be *something* useful to them right? No so far as our family can see. It's now used by my youngest to play games like Angry birds.
I hoped one use case would be the one suggested by the AC of connecting to a remote desktop. But that really only works if you have a keyboard and mouse (I've really tried to use a stylus). I bought a keyboard with integrated mouse but then I have to carry a heavy device or have it propped up so I can see the screen and a then plug-in keyboard (the on screen one is useless). How is this better than, say, a laptop given the laptop costs less!?!