Task running is more what Ant is for, isn't it? Maven is more of a dependency management tool than a task runner. A lot of Java projects use both tools together for builds.
I've never used it, but MSBuild sounds like Microsoft's version of Ant to me.
MSBuild has a lot of Ant-yness to it, yes. However, I quibble with your definition of Maven as a dependency manager--it has one (and the independent implementation that can work with Maven repos is Apache Ivy) but I've never seen a Java project use both. Usually somebody jams some sort of runner into a Maven project as a different build step or something.
Yeah... I've also worked on corporate Java projects with no Ant, Maven, nor hand-rolled substitute, where the build process was to download the dependencies' jars from the internet manually into /lib.
Of course! That's why the Java world uses maven
It makes no sense, but hey, it's XML