I use Dreamweaver as a code editor and really like it, but of course I use it for HTML, PHP etc as well. (Note: I never use design view. ) I’d hate to do different code in different editors. There are all sorts of features in Dw that make it handy for code editing. I also use TextMate and Coda on the Mac, and often just plain old TextEdit too!
Dw has code collapse, code highlighting, missing tag/quotes highlighting, code indenting and code formatting options as well as built in validators, references for css, html and javascript, code suggestion and built in ftp facilities.