I've suspected for a long time that many, if not the majority, of developers at Microsoft, at least on product teams, don't use Visual Studio. I'd bet that most devs at Sun don't use SunOne, or whatever they call it these days, either.
What aggravates me about Eclipse is that sometimes, you just need to edit a file; in Eclipse, the file has to be part of a project. I know that this helps avoid problems where you end up with resources that aren't source controlled, but it's still too restrictive for me.
This is starting to look a lot like a cultural issue to me. We Smalltalk developers have been known to say (and I'm sure others find it annoying): "Source code in files. How quaint". There's a reason we say that though - in Smalltalk - unlike most other environments - the development environment is the deployment environment and vice versa. There are no files to aggregate, edit, and compile; there's the image (yes, I know some Smalltalks are different; I'm talking about the more commonly used ones). What that does is create a very different development world view. Additionally, our methods tend to be short - for me, methods longer than 7-10 lines of code start to positively smell. How does that tie in? Well, just how powerful does the editor need to be when you are dealing with 7-10 lines (at most) most of the time? Not very. This is one of the reasons that power tools like Emacs just bore me; The Smalltalk environment is more programmable, and I'm not dealing with large amounts of text anyway.
Bottom line, I think the folks dealing with curly brace languages have a different view of development from Smalltalkers, and part of it involves needing/wanting a more powerful editor.