Not to mention that some of the "new" SoU content, like prestige classes, spells, monsters and feats should have been in NWN from the start. Of course I can see their point of view: If they can sell expansion packs (a second one is on the way to introduce Epic levels) they can make more money out of the game. Though it doesn't take away the fact that most of the new content is standard 3E DnD stuff and should have been in there already.
