From a hype point of view the tablet market dates back to the Apple Newton which shipped about 1993. This device pretty much popularized the PDA (Personal Digital Assistant) craze of the 1990's, which morphed into the Smartphone craze of the 2000s. Now thanks to Apple again we now have the tablet craze of the 2010's.
In 2001 Microsoft announced the Tablet PC, which never really took off all that well. Now fast forward to 2011, with the success of the iPad and iPad 2, we are now seeing a plethora of Windows tablet devices again from several manufactures.
For me personally, I think I would like the idea of a Windows tablet, because its would a good medium point between a smartphone, and desktop where normally I would use a laptop. From an OS platform perspective, I like the flexibility of Windows vs some of the other options like iOS or Android.
Below is a list of feature considerations for a Windows tablet: