Actually, it depends a bit on the user. The back lit screen for reading is one of the things I'm most excited about. I just can't see digital paper technologies like the Kindle... they just don't have enough contrast.
A back lit screen might not be great for reading on a sunny day, but for someone like myself, who has had to give up reading actual paper books because I can no longer see them, and is stuck reading only eBooks where I can have a back light and enlarged font, the iPad is exciting. Finally, I'll be able to relax on the couch again and read comfortably, rather than having to sit at my desk.
I do realize I'm in the minority when compared to the overall consumer market, but there are a lot of visually impaired users who would actually benefit from the back light.