The Software Lifecycle Guys at Avanade launched a new blog about a month ago with a focus on the software life cycle and a category dedicated to Team System. In this post, they discuss creating a transform for performing an unattended install of Team Foundation Server.

It's not supported at present, and it was not easy to figure out, but it is possible. For example, to peform an unattended install of the application tier here are some highly abbreviated tips.

The Software Lifecycle Blog : Unattended install of Team Foundation Server.