Just wanted to say I picked this up over the weekend. Beamdog is doing an early access thing that they are calling a "head start". At this point I'm just playing through official stuff again, but it seems to work great so far. The first NWN was always one of my favorite games, so I'm definitely a bit biased, but I don't regret my decision yet.
My understanding is that the vast majority of community created content works just fine already, though the folder structure was altered a little bit to work with newer versions of Windows, so even mods with installer programs will probably require manual intervention. I did read on their forums that they were unable to license the bink player, so custom movie files need to be converted to something else (webm I think). Once converted it sounds like they work fine though and the game picks them up without a problem. Again, I haven't personally tried this, so take it with a grain of salt.
The graphics are improved, though the game is still fugly as hell. However, if you loved NWN as much as I did then this looks like it will probably be a pretty good buy. it seems to have sparked new interest in the tool set, with some former authors returning to update their creations and now talking about maybe making new modules. Beamdog is also talking about creating new custom content once they finish getting this out the door.