On a project that I'm working I recently converted a ~260 line Rakefile into ~150 lines of gulp ... and our build is now almost instantaneous (took a few seconds to do with Ruby, mainly because we had to shell out to things like the less compiler). Oh, and we were also able to build our gulpfile.js in just a few hours after hearing about it for the first time.

I never went the Grunt route because I just can't get used to programming with massive, multi-tiered object literals. If you've ever seen a Gruntfile, you know what I mean. It's all configuration, very little real code.

With gulp, code trumps configuration. And the result is incredibly concise and fast. I would definitely encourage anyone who has been looking for a decent build system for JavaScript to give gulp some serious consideration. We were pleasantly surprised with the community support as well. There is already a wide array of community plugins for gulp that support many common use cases.