Minifying the JavaScript distributed to a browser is important for performance. The speedy module came into being in an effort to make this easy for Drupal sites to implement everywhere. Today the 1.0 release of the module comes out providing minified JavaScript for Drupal 7 core.
Path Forward
While there are many performance problems we can solve over time we want to get those that work out there as quickly as possible. In the speedy issue there are more features we are hoping to add over time. The initial release is just one step to better performance.
Default JavaScript to Footer
Unless you have a reason to your JavaScript files should be included in the footer. By default Drupal places them in the header which is a much safer approach. When included in the footer there are times this won’t work well. We are working to make the footer the default except for cases it shouldn’t be.
A Pluggable System
While I use UglifyJS to minify my JavaScript there are other tools. Some you may want to automate into build scripts or some other method. For example, using an external service to generate the minified files. There are a number of issues in the speedy issue queue targeted at making this work.
Minified Contrib JavaScript
One of the hard problems to solve is to legally minify JavaScript libraries included in contrib. If a library is include in a module with license information we have to be sure not to remove that. We want this module to be safe for anyone to install without worrying if they are violating any license. This is one of those non-trivial problems to solve but we are working on it.
If you would like to help please join the issue queues, create some patches, start some git branches with changes, write some documentation, or even just spread the word. JohnAlbin and arthurf already have.