I think a good enhancement would be to allow people to put the editor into lower-case mode. When I do my coding I like to do everything in lower case, except content such as image URLs and body text.
In other words, when I make a form I like it to say method="get" and not method="GET". When I add a hex colour I like it to be f5f5f5 and not F5F5F5, etc.
I find this looks a lot better to be eyes, and keeping everything consistent is a must so multiple people can work on the same project easily and such. While WeBuilder does a good job of keeping in line with XHTML's need for tags to be lower case, but I'd like it go that bit further.
Perhaps I'm just being too picky here, but seeing this option in stuff like TopStyle Pro makes me miss it in WeBuilder. I only want stuff to be upper case if I specifically make it upper case myself.