If you look on the project page for DOD you will see a small addition to the description. Apparently they have been working with BD to create an Enhanced Edition version with added content. The link in this new addition to the description takes you to the official announcement. On that page there is a link to the steam page where you can buy it.
Talk about low-key announcement.
[Edit]
Typical, while I was writing this, the announcement appears on the front page of this site.
TR
Only on steam. 
Which sucks
Haters gonna hate.
I would rather give my money straight to Beamdog or Ossian, instead of a 3rd party. I know steam is going to open up a lot for the multi players and that’s fine by me, but I play single player and don’t see steam as option I really want to do.
I read that direct purchase from Beamdog is coming soon…
Looks like steam are including it as part of their version of the digital deluxe package.
TR
Steam is just as much an option for SP as for MP. And BD will be selling it soon as well.
Good, because I’d prefer to give my money straight to BD/Ossian.
Looks like it is not only coming to BD either. Reading between the lines on this BD blog, where they say -
Neverwinter Nights: Darkness over Daggerford is now available on Steam for $9.99 USD and will be coming soon to
Beamdog.comand other stores.
I would say that it is probably slated for a release on GOG (once the negotiations to release NwN EE on there are finalised) as well.
TR
But will it be locked like the other premium modules? If I can’t look under the hood, I’m not so sure that I’ll buy.
This is a long overdue act of justice for the principals at Ossian. I’m very glad to see it.
Anyone knows, what was exactly changed (except of graphics improvement, new soundtrack and numerous bugfixes) from 1.69 version, which was for free? Was some new plot added? New NPCs? New functionality, items, spells, classes?
If not, I’m not interested.
BTW: does this mean, that BD can take one of my modules, improve it graphically and sell it? I know that it’s extremely unlikely occurrence, but it makes me wonder, if BD has any rights to already published modules and CC.
If you check out Ossian’s own page on DOD EE it becomes obvious that they have done this, with some input from BD, themselves. If you prefer there is the change log that lists all the changes from the original.
TR
Thanks, TR, that was the information I’ve needed. Hope that Ossian will be successful and encouraged to create some new stuff. DOD was one of the best modules I’ve ever played.
But for me the price is just too steep /for a premium module/ 