>> The problem is, once you're lugging around a keyboard, you might as well lug around a laptop as well.
> Not entirely: a folding keyboard can fit in a pocket. It doesn't require a laptop bag over your shoulder, you can just put it in your pocket in the morning and forget about it until you use it.
Besides this, in many places that you will be using the tablet for desktop type work, you may have a real keyboard sitting there (just like people do for their laptops in many cases)