It is essential to be able to specify the VM
options  from the project properties in Running
Tests sections. Absence of such options may make
it impossible to run the tests in the same
environment as the project itself if the VM
options (-D or -X) are used to control the JVM
behavior. 
In my case, I can't run tests explicitly
specifying default JVM encoding using
"file.encoding" property (which must be set from
the command line) without hacking through the
project files manually. IMO such types of problems
are quite common.