The Nightly Package Builder(NPB) is the first service we announce. It's currently in a testing state but we will release it soon.
The NPB doesn't build packages directly. But it prepares the source packages, keeps track of the dependencies and uploads them to different Personal Package Archives(PPAs) at launchpad.net. All build processes are triggered by hand at the moment. But we will let a CronJob do this for us in the near future.
For more information have a look at the Nightly Package Builder web page.