One thing I'd highly recommend is LyX (http://www.lyx.org/), a
what-you-see-is-what-you-mean GUI frontend to LaTeX. It's excellent for
banging out a double-spaced document with footnotes very quickly (same if
you want to add margin notes, endnotes, mathematical formulas, tables, and
diagrams). Its only disadvantage (from the perspective of a Yale paper
writer, at least) is that it's hard to figure out what page you're up to
without doing a full LaTeX run, and knowing what page I'm on at all times
is a great boon to me when I'm dredging my way through a paper that has to
have 8-10 of them or whatever.
(It is fairly easy to get a word count with LyX, though. The
feature isn't built in, but you can go to File->Export->Custom, select the
ASCII button, and send the document to the command "wc -w", which'll print
a word count on your console.)
What else... another thing worth keeping an eye on is AbiWord
(http://www.abisource.com/). It's at version 0.5.5 right now and doesn't
look like it's really usable yet, but it looks promising.
Matt