Yesterday, we deployed our sprint 38 work to the service. You can read the release notes on the service here: http://tfspreview.com/en-us/home/news/2012/oct-29/
Other than some bug fixes, this sprint was primarily about our build automation features. We announced the new build drops feature, the ability to download builds as zips and the ability to view and download build logs. Later today, we are also updating our build image with the latest Windows Phone SDK so that you can use the build service to build Windows Phone 7 & 8 apps too. I’m sorry this has been so long coming but we’ve had to wait for the Phone team to provide us an SDK that we could host on the service. I’m very happy to have it now!
Next up for build will likely be adding support for building Windows 8 store apps.