I wouldn't say you need to actually learn Groovy to get going with Gradle. The example build.gradle files are fairly self-documenting, and you'll be modifying them more than writing them from scratch.
In that case I will have to check in out on a side project. My current projects at work are using Ant or Maven and I dont really like sorting through the pom.xml especially if someone else set it up.
Easier to read than a pom.xml, for sure.