Bandwagons come and go, when looking back there are so many which fall in to the category "forget/can't believe I jumped on" but with the rise of require js and other module loaders using the commonjs Asynchronous Module Definition I think this is one bandwagon everyone should be considering seriously.
In my position at the digital agency I work for, I've been considering the ever widening landscape of client expectations from new forms of UX on devices, locations and interactions within social circles. More and more is being requested and without modularising these features in to well tested silos the time needed to satisfy clients hunger could potentially sky rocket.
One of the things I love most about being a front-end developer is the way our community collaborates. I'm a big fan of open-source contributions and I try to release anything I think could be useful. We are in exciting times with services like GitHub and BitBucket providing the platform to share and enhance others code. What we are often lacking is the skill and experience to build modular code which can be easily plugged in to each others projects.
Practice with Kata
One way of improving your modular programming skills is by doing Katas which is exercise based on the Japanese concept of Kata solving small problems with repetition to hone your skill. Here are a few katas to get you going.
With Power Comes Responsibility