I think you guys are reinventing the wheel here with respect to building addons. Gyp and CMake were create specifically so you don't need to roll your own system. Maybe it is just me but I liked the fact that node-waf came bundled with the node install. This meant that I didn't have to go fetch any additional packages or items to build the addon.
I will also add that I am against shipping binary addons. The number of "parameters" you could be pivoting on is too great imho. If someone has a system in place to deploy binaries (deb, rpm, etc) I would think they should use that. Otherwise compiling these small addons for deployment is not that big a deal is it? I would be hesitant on a binary solution until someone can prove to me anyone would actually care to use it in a meaningful way. Right now, I just always build when I deploy and that works fine. The benefit here is that build time failure is much preferred to run time failure.