Fow what it's worth (not much, likely), I'm a definite -1 on multi-row tabs. The typical MS-style implementation is a UI horror show, as someone alluded to earlier.
Perhaps some kind of indicator in the drawer for open files would be a useful compromise?
(And as long as I've suggested that I'll slip in the suggestion that the drawer items could visually indicate saved/unsaved file state, too -- that's done in many other apps and is quite handy.)
pb
-- Paul Bissex http://e-scribe.com/news/ Northampton MA USA 01061-0847