I have a very beefy PC and noticed that the campaign map started lagging somewhat, and then I eventually got a CTD.. For whatever reason I noticed I had about 30-40 save files going, so I decided to delete them, and suddenly the campaign map wasn't laggy anymore and I was able to make it further into the game without a CTD. I haven't any idea why there would be a connection, but it's something to check out. Of course, way later on I got more CTD's, but the campaign map wasn't laggy anymore.
Who knows. Hopefully we're getting our fix soon. I'm also counting on some gameplay changes as well, such as the enemy using ships to invade other lands. That's almost a gamebreaking bug in my eyes.