You will need to remove the mod before you patch your game and wait with putting it back in until Twallan says it's ok. It might need updating, it might not but that can't be certain until generations is here.
Overwatch is neither an injector nor a core mod (no, you don't need to know what that means exactly) so there are no special uninstall instructions for it. Simply delete it from the mods folder, delete the cache files and it will be gone.
I always suggest, that you start a new testing game and backup everything before installing any patch. Also turn off automatic updates. If you plan on getting generations, don't patch your game from the server. Wait till you get the DVD and patch from there. It's going to be the same patch. If you get the download version, I'm not entirely sure how it works but I would assume you will need to download the patch and then download the EP.
Here are a few tips: http://crinrict-help.blogspot.com/2011/01/tutorial-what-to-do-before-patching.html
and a small faq an patches and bugs: http://crinrict-help.blogspot.com/2011/03/faq-bugs-patches.html
As for my plans on Generations: I probably won't be getting it right away. I've not been playing the game for a while, so it would be a waste of money at this point in time. I plan on making a bug thread but I will be on vacation from the June 8th for a little over a week. I don't know if I will have Internet there or not but probably not.
