As my first post I decided to trow in a feature request that may have been partialy discussed, but I don't think I have found it in a similar form to what I want to post here.
Is it possible (since we are now getting BG1 and BG2 both on the exactly same engine) to create an unified launcher and to create the game the same way as Starcraft is created in episodes? This would include a common world expanding with every expansion and "next game" purchased and added, that would be included in the final game.
This "unified" game would allow You to travel back to locations from BG1 after You start a BG2 game based on "saves" from the first part of the saga. This would have to include character migration, but also keep track of quests completed before on locations that would be transfered (maybe also with some sort of additional quests available on BG2 level in old locations after You finish BG1?). What we would get eventualy is pretty much like the world presented in "big picture" with additional content based on players progress. This could also allow to "reuse" locations that are part of the original game to get back to them and keep questing with their inhabitants "carrying on", new forces taking strongholds and camps that are left after all bandits have been killed in BG1 etc.
Finaly there is also a world big enough to create a whole line of additional content based on side characters (maybe a story of Xzar and Montaron between events form BG1 and BG2?) that would be playable after You main character has become a god in the TOB finale? Unification of these two world maps, locations and quests is also a great way to significantly extend games life after release.
I am aware that changing encounters, or rearranging dialogues may add many bugs, and rebuilding locations is in many cases impossible, but there are still many "doors" that are not clickable areas, and that could be utilised by all the content. One clickable area on a never used door can lead to a completely new locations built from scratch ... the only thing that is the limit is how much time You have to create everything, and since it can be released after the core two games - it's almost unlimited in a matter of getting more and more packed here!