It seems you have missed quite a bit over the last months:
http://www.pcgamer.com/icewind-dale-2-cant-be-enhanced-because-the-source-code-is-lost/

Thx, for the info. But they could release it as is.

引用自 Dmitry Vorobyev：

But they could release it as is.

No, they can't for various reasons. They are not the original developers, and they are not the original publisher either. Even if they acquired permission to do "something" with the original game files, they would be unable to add Steam support to it. Any issue that would come up could turn such a release into a nightmare.

If you want IWD2 so badly, your best bet currently is -->
https://www.gog.com/game/icewind_dale_2

Ye, i have it there...

Did anybody ever mod IWD2 for widescreen support? I remember the UI not scaling right, but it's been an age since I tried playing that game.