What alternatives exist to Spring Batch to handle queued jobs?
Batch support is now available in Java EE 7 via JSR 352: Batch applications for the Java platform.
See Batch Applications in Java EE 7 - Undertanding JSR 352 Concepts for some more info.
Well the uber-king of big-data batch processing is Hadoop, but that can be rather tricky to set up, to put it mildly.
Akka is a nice solution too for precessing small tasks http://akka.io/