I've been trying to convince my Web Design teacher to use three text editors: MS Notepad, Araneae, then Adobe Dreamweaver CS5.
He teaches HTML the first quarter, and I think Notepad takes care of that. The second quarter he goes more into designing different things, and Araneae expands on these things really nicely.
Then, at the end of the year he teaches how to use "professional tools like Adobe Dreamweaver". I don't particularly like DM because it's far too expensive and memory sluggish.
But, I think Araneae will start to be used in the web class at my school!