Linking references to spscific parts of an article is important, but I would be less concerned about that than about articles that have no references at all. Adding references is indeed a pain in the ass, and even more so when you did not write the article. Someone who encounters an article with no references at all may have no idea where to look for information about it. The original contributor presumably had references right there when he wrote the article If he didn't, and wrote from memory, we have no way of knowing whether he is perpetuating some sort of urban myth. Your idea is constructive, and it makes the physical process of adding references a little easier, but I don't see the problem of references as primarily at that level of the process. The writers just need to do their own basic research.
I think it makes the process a lot easier in many ways, though. For instance, if one is merely adding to a single section, adding a reference takes two edits, one to the section, and then one to the references section. And then, if you're going to go through that trouble, you really should remember the format. Being able to stick a url or an ISBN into a field and have the reference generated automatically would be a *huge* time saver.
I wonder how much Google Print and the others are going to help this task. I don't use Google Print that often, but it seems this would greatly improve the likelihood of finding a reference for all but the most obscure of facts.
Anthony