Good initialive, although I'm surprised to see Stylus in that stack: I like stylus and nib very much, but now that there is libsass which doesn't rely on Ruby (and even compiles faster, although it doesn't support some 3.2 and 3.3 features as far as I know) and a matching npm module [1], and until there is source maps support in Stylus, SASS might be a better choice for newcomers.
Good idea :) I also just added a reply because turns out Stylus added source maps very recently (today even ?), so the lack of sourcemaps is not a problem anymore.
[1] https://github.com/sass/node-sass