I understand your point. I use a text editor usually, but lately I've used Eclipse with java for a fairly big project (with a team and svn ecc).
And it seems to me that for the way web application are moving toward client-side, the bulk of the code will be on javascript in the future or a greater chunk of it.
What I liked about Eclipse&java is of course code completion (for the logWordsJavaUsesForClassesAndPackage) but most of all the order it brings to all of that comlpexity (classes, packages, enums, the use of different patterns ecc).
if think the more we go toward a complexification (does it exists in english ;P) of javascript projects, the more we are going to need something that bring order in the chaos.
Otherwise we will be a bit overwhelmed by the code of a language not born to do what we are using it for today.