I think randomization is possible, but only to some extent.
(From my experience with IWD2, it's not a game I'd like to play again. With IWD, while it's better, I'm not sure people will play IWD+ IWD NPC more than once. Twice is my best estimation, and only for the die hard Xan fans.
Hey, I love PS:T, but I only _really_ finished it once. So I'm rather
realistic pessimistic here).
I tried to adapt jcompton's banter accelerator at first, but it didn't work so well; it's out of the question now. However, this may(I'm not saying will, but it may be an alternative) work: all banters are depending on particular events and areas, but I could use Random(2,1) or RESPONSE #50, and to trigger banter A instead of banter B. I promise to think about it, and seriously.
But there's another problem: most(not all, because I like my light-hearted banters and humor and Mot Making Sense, too) NPC-NPC banters are exploring the characters, they are giving vital information, and I'd rather not skip them. And, again: there are banters I could randomize, and writing more is not a problem, but it'll give more work to voice actors.
I'd like to think about it some more. Opinions, naturally, are welcome - I'll split the topic, starting with this post of mine, if you like.
And, all right, I'll try to remember about the previews. Every time I promise something, I get buried in writing/testing/playing the Trials of the Luremaster for the first time ever, and so... yeah.