I'm hoping this email will get added to the right message thread (don't know how to reply to a thread made before my subscription...)
OpenSSL works fine if you use the 1.0.0 daily snapshots. I understand that may not be a possibility for you, but the plain 1.0.0-stable-SNAPSHOT-xxxxx sources work fine. The snapshots can be found here: ftp://ftp.openssl.org/snapshot/
One note: if you're using mingw-w64 with the new underscoring (nu underscore in symbol name for x64), you will need to modify the sources according to my instructions here (one liner in a perl script): http://rt.openssl.org/Ticket/Display.html?id=2273&user=guest&pass=guest
My build is also uploaded on the mingw-w64 sourceforge project page: http://sourceforge.net/projects/mingw-w64/files/External%20binary%20packages%20%28Win64%20hosted%29/Binaries/new%20%28for%20MSVC%20and%20mingw64%20after%2020100427/OpenSSL-1.0.1pre-bin-x64.zip/download
Don't know how helpful this will be, but it's there anyway...