That's tremendously difficult given security concerns. Not only would build servers have access to source code, but they would also be running arbitrary user-supplied code of an indeterminate nature.
I'm just surprised they wrote yet-another-build-server with a small feature foot print -- but the more the merrier. More software around automated building is a good thing.
Yeah very true. The providers that are doing are doing constrained things like Rails CI. I think thats fine, I just need a place for my smaller client projects that can run Rails or Flex unit tests without me setting up a dedicated slice and having to manage that.