I've not looked closely at the implementation, but Python concatenating adjacent strings might be a relic of C-based languages -- the same rule applies there and likely a standard of the language with CPython being the default underbelly of Python.
Then your final (YUI) example, we have "random" commas. Again, the language syntax starts to trend towards generally inconsistent, and I have to enforce more style guides upon my team.
NOTE: I work heavily with YUI as well, and my team -- Python stack -- too writes shims to support "kwargs"-like syntax, so I can't really consider coffeescript having an advantage. Quick pseudo comparison...
YUI.module = function(name, func, kwargs){
kwargs = kwargs || {};
return YUI.add(name, function(Y){func(Y);}, kwargs.version, kwargs.details);
};
YUI.module("myCoolModule", function(Y){
...
}, {"version": "1.0.0", "details": {"requires": ["app", "model"]});