This will certainly work in an exclusively *nix environment. However, if you need your build system to be Windows-compatible, you'll need to go with something like Grunt.
My team decided to just forget about Windows, and only use Linux or OSX. It is so much more convenient when you can rely on Bash, Make, and Unix conventions. (It is interesting discovering the slight incompatibilities between GNU core utils and OSX core utils, though, but usually the GNU versions just have extra features.)
Make plays nicely with npm once you set the PATH to include ./node_modules/.bin . Watching is the only thing Make can't do, so I usually set up a very simple Gruntfile that watches the source files, launches a livereload server, and just calls `make` when anything changes.
