I managed to get the 90 day trial version of Visual Studio 2008 and figured out how to build x64 versions of the plugin. http://www.farfarer.com/blog/2012/06/12/unity3d-tangent-basis-plugin-xnormal/
Sorry this took so long, the Visual Studio project ended up with wrong settings somehow having set it up in 2008 rather than Enterprise but I finally sorted it out (it's all complete jargon to me). Also discovered the versions I'd released previously were still in unoptimised debug mode, so hopefully this'll be a little…
Hey, This is awesome, thanks for this. =] I was wondering if the Unity guys ever released their tangent basis that they use or is what you have a super close "guess" that looks ok 99% of the time. -edit- Actually... never mind, just checked out your blog post where it says the unity guys released the source code.
Yes it is, but with very high res meshes, you have to deal with Xnormal at the end. and Xnormal produces better AO andplenty of different useful maps you know :)