You don't have to use that. Meteor has had built-in support for npm since something like v0.6 (~two years ago). You need to declare your npm dependencies in your package.js but then you can go ahead and use `Npm.require`.
As someone who has been building on Meteor for a while and using many npm modules, I've never actually heard of "meteorhacks:npm", and to be honest I'm confused what it's for...