Back to the point of this conversation.
I agree that [community] should be enabled by default. My reasoning is quite simple: all packages in community have been tested by/are maintained by TUs. This should be reason enough to trust the packages in that repo. If you were to use the argument that community packages were less stable or somehow less well maintained, what is the point of having TUs? The very concept of having TUs is to ensure that community packages can be trusted -- hence the name.
My $0.02
-- Rob