Lots of people seem to be getting excited about Mule and MuleSource. I would too if it weren't for sentences like this:
Mule is a messaging platform based on ideas from ESB architectures. The core of Mule is a SEDA-based service container that manages service objects, known as Universal Message Objects or UMOs, which are plain old java objects. All communication between UMOs and other applications is made through message endpoints. These endpoints provide a simple and consistent interface to vastly disparate technologies such as Jms, Smtp, Jdbc, Tcp, Http, Xmpp, file, etc.
I found this interview with MuleSource's founder and CTO Ross Mason slightly more illuminating. I'm sure I'll get the hang of it all eventually.