NW Vault has an interview with the Ossian Studios team, developers of the upcoming adventure pack, Mysteries of Westgate. Here's a portion of the interview:
Can community modders use the custom content in their own mods and can you tell us a bit more about what you have added?
Alan Miranda: That's the plan. We would like to give fans our new creatures, new tileset, and new music to use. Modders deserve to get as much as they can to create their own adventures. For example, one of our new creatures is very versatile for many kinds of environments (versus a unique creature specific to one environment), so it would come in handy for many modders, especially in conjunction with our new sewer tileset, which is a tileset that currently isn't found in official NWN2 resources.
If so will they be provide in a HAK with their content in it conveniently packaged?
Alan Miranda: This is something we're still looking at. The options are that our content will either be integrated into official NWN2 resources or will be distributed via a HAK.
Be sure to read the rest at the Vault.