I have one of the non 3G keyboard equipped Kindles - I've never really used the keyboard, as I don't tend to annotate books, and I've never felt the need for 3G. I'd imagine it would only be of value for downloading books, as trying to browse the web on the e-ink screen is pretty frustrating. I guess it might be handy if you were abroad for work a lot, but that's about it.
I'm tempted by the Touch as well, as the only real niggle I have with the Kindle is the buttons on the sides are right where I want to put my fingers when I'm reading. The big unknown might be whether the finger marks would become distracting on the screen, although it might not be a problem as the screen's not backlit.