You all had written asking for Windows users to write in with what worked, what didn't so that you all'd be able to improve for future releases. I'm including the steps I went through in getting my install going. I didn't quite make it, but I overcame a couple of issues I was having, hopefully this'll be useful.
1. I have multiple texmf directories. One managed by MikTeX and one local I manage myself. It'd be nice to not have to worry about that.
2. The Git Bash uses the MSYS program; many windowzers might already have it without having to download&install MSYS.
3. Many windows folk used the pre-patched windows emacs intalls available here: it might be worthwhile to mention it, so folk aren't scared off thinking auctex is incompatible with them
4. Under the --infodir=DRIVE:/PATH/... option, it stipulates that 'If you are installing into an Emacs directory, do X'. It wasn't initially clear to me what an 'emacs directory' is.
5.** ./configure. The makefile generated in the /doc, etc can't find files listed in /c/Program Files/... or anything outside my basic user directory
I had to rename /c/Program\ Files/MiKTeX\ 2.9/miktex/bin/x64/dvips to "C:\\Program Files\\MiKTeX 2.9\\miktex\\bin\\x64\\dvips" to make it work. Note those quotes were a part of the variable assignment.
6. I had to do the same with the calls to tex and pdflatex and latex
For some reason I couldn't get them to work in that exact fashion (i think it may have been a privilege or rights problem, but I couldn't ascertain -- I was running as an elevated user) Anyway, what I ended up doing was symlinking the MiKTeX binary directory to some place in my userspace, and then changed the filenames to point to that.
7. Even after successfully make-ing, make install gave me some interesting issues. basename program wasn't running on the command line as it ought.
I think there might be an issue with backtick running under MSYS or git bash on windows. I just renamed the file to what its supposed to be in my instance "tex-site.el". Yucky, though.
8. I got as far as mv-ing the generated file to site-tex.el not working, just a *few* steps away, and I just don't have any more time to putting into this.
Thanks so much, and hope this helps somebody. Lemme know if I can offer more clarification or help in some fashion.