If you're talking about backstory and hint books... it looks like everything that isn't a consumable or equipment was discarded. Most of it is still available to be found again in FoV but if you like keeping your novels, you had to start over again.
It's not just me, then: well that's something at least, and my tendency to hoard stuff probably isn't one of my more useful traits anyway.

And if by cameo you mean corpses, then yes. It is a rather annoying mixed message. There is an excess of nihilism in D2. There seems to be two classes of characters. The typical high fantasy where every named character seems to have a greater purpose, such as yourself and anybody else that's a great wizard, sorcerer, dragon, etc. And then you have characters that amount to empty shells. You meet them, a little depth is added and then poof. Its like the characters never even tried to escape their fate. Seemly like a group of extras in a movie whose purpose is to be stomped on by godzilla. Its oddly distracting because there seems to be no apparent reason why they can't be the type of forgettable faceless souls that gives one or two line non-conversational dialog. Of course, some of them are simply there to fulfill a game mechanism. But still, for me the utilitarian purpose of the character appears to break the illusion of suspended disbelief. Is a character's worth only what he/she can do to maximize his/her practical function?
I did mean the corpses. I agree with you there, it does seem that non-key characters seem to be somewhat like the "red shirts" in Star Trek. I happen to like background characters, though, to the point where I've modded the likes of Oblivion and Fallout 3 to make all but the most unpleasant essential so that I don't find myself wandering through an empty world. Well, that and the fact that I like a lot of them. So from that point of view, I was sad to learn of their likely fates and that more of them didn't successfully find refuge in Aleroth. Well, for values of "successfully", given the state of health of those we did meet.