DAV is everything I hoped, and more. In addition to being really easy to install and enable, it is really really easy to use. I'm using the 'cadaver' client, which acts like a command-line ftp program, except that it launches $EDITOR when you 'edit foo.html'.
DreamWeaver, on the other hand, lets you edit files, and appears to keep some kind of local copy of the modified files, only putting them up when you are satisfied with them.
This will, it seems, let me ditch FTP once and for all. And it fixes all the annoying permission problems that I always have with multi-developer web sites. Using some form of http auth, rather than user logins, allows me to create "logins" very easily, withouth having to create system accounts and hand *those* out like candy.
So, I sent out a company-wide email telling folks that they need to experiment with this, and that we'll be moving off FTP RSN. Yay.