In my own research on this subject, I’ve found a population of users, generally in their 50’s and 60’s who don’t work in an office every day, and have a cause they care about outside work. Initially using their tablets for this non-office work, they found it worked well-enough (especially with a keyboard) to use for their office work while on-the-go. Fonts can be displayed bigger with a simple gesture, it’s lightweight, and with the right apps, enables them to create and edit documents without lugging a laptop.
From what I see, the biggest obstacles occur when devices and apps that force a specific interaction paradigm, rather than get out of the way and let the user focus on the content s/he wants to create or share. The value of the tablet to this crowd is the anytime, anywhere independence it enables. Today, when formatting is important, they return to the laptop to clean up their documents, though apps done right will just do this for them, and, not make them choose how to express something (spreadsheet, word doc, presentation) before expressing it.