I've been using a Hp tablet PC, windows 7 and OneNote (http://en.wikipedia.org/wiki/Microsoft_Office_2010). This seems to be a very good solution for me, I can use all my desktop data, anotate with the pen, and when not using the One note touch/pen interface I can swivel the screen around and use like a laptop (keyboard etc).
I travel around alot and need to gather a bunch of "freeform" data, I can take some pictures, embed them into my documets, write a few notes next to them, send them off to various mail accounts, download some data from the net, and when I get back to the Orfice, connect up to the network and share the whole works whith a few co-workers.
I don't really listen to a lot of music or watch movies with it, (although I did spend a week out in boondocks of Wisconsin and the netflix account came in handy) I guess you get what you need and leave it at that, often I think that most of the hype is created to sell advertising copy.
When all is said and done, you figure out what you need to do, and then get the best fit.