Since the BG2 modding community is quite big and active there were a lot of debates and in the end in these days the installer is in version 9.2, it's fully automatic, and its made in a way that pleases both modders and players, and I think if that model would be adopted by the oblivion community it would be a huge step forward. Here is a link to the main http://www.shsforums.net/topic/44661-big-world-project-bwp-v90/.
The way thats organized in short is that there is a user interface called Big World Setup that lets you choose the mods that you want, the type of install, with a minimum of recommended mods or a selection of mods that make the game more challenging, and after the choices are made, the BWS downloads the mods from the official modders pages. After the download is finished the BWS unpacks automatically all the mods in the correct folders and after a check it closes and opens the Big World Install. This one installs correctly all the mods in the right order automatically and after a few hours you have a fully functional modded BG2. Its very nice and VERY user friendly, and it helped the community grow a lot since it was developed, both modders and players.
I am curious if anybody would like to initiate such a successful project here, inspired by such a model.