If you want to run multiple WSO2 Servers (any type .. e.g. ESB, AS, GReg etc.), you can easily switch the ports using the Ports/offset property in the repository/conf/carbon.xml. When a WSO2 server starts, it listens on several ports. Offset moves all ports by the given value, and very handy tool when you play with things.
Yes does not make a huge difference on a production deployment, but a remove a major pain factor if you are playing with stuff.