`grunt.loadTasks('foo')` loads all JS files under directory `foo`, not `tasks/foo.js` with grunt v0.4.0rc2.

Gruntfile.js

// ./Gruntfile.js
module.exports = function(grunt) {
	grunt.loadTasks('hoge');
};

Shell

$ grunt hoge
`hoge/xxx.js` is loaded!
Running "hoge" task
Hello, hoge world!

Done, without errors.

xxx.js

// ./hoge/xxx.js
module.exports = function(grunt) {
	console.log('`hoge/xxx.js` is loaded!');

	grunt.registerTask('hoge', function() {
		console.log('Hello, hoge world!');
	});
};

+6 years, still works :)

you know, i needed to search for this again, and just noticed my own comment from last year...
7 years, going strong.