Since we are getting a new skill tree, it would be very nice if we got a day of free refunds for our existing skill trees.
I don't know about the rest of the people, but I have invested a lot of books over the years in some skills that are no longer useful to me at all (for example Geologists' skills for certain deposits that I no longer have to look for). That's just an idea, of course, but I'd be very grateful if BB took it under consideration...