If you desire a Linux/Mac Port of NWN2 and you haven’t already, please post so in the following thread:
NWN2 will ship supporting DX9.0c only. There are currently no plans for anything else, and only Atari can make the decision for an OpenGL version of the graphics engine. Asking for one here doesn’t improve the chances of a port; if you want something, you have to ask the right people (see link above).
Will NWN2 run under cedega? Nobody knows (the game had not been release yet), and as cedega is 3rd party software, the developers and publisher of NWN2 can make no such guarantee.
Further requests for OS ports will be considered off-topic and locked/moved. Thank you for your cooperation.
The Atari thread for Linux users is currently at 11 pages.