The DR1000SW has been "upcoming" for almost a year now.
Yes, they've said that the plan is to develop a web browser for the DR1000SW that would also be portable to the DR1000S. We can assume that would mean it could also be ported to the DR800 (since they've indicated that applications should be easily portable between the two).
That's all based on the DR1000SW becoming a real product though. I've never heard any announcements about a release date, for whatever that's worth.
The other possibility is that they've written a browser specifically for the DR800 from the beginning. We probably won't know that until more details come out.
I don't know if the 3G downloads will be done via a browser interface to a B&N website, or if it will be some sort of dedicated app. I haven't seen that covered in any of the reviews (at least, not that I've noticed). I could see either option being viable.