Thanks to Andy Reay for providing this update:

A set of 200+ MS build tasks was recently released to CodePlex

See: http://www.codeplex.com/MSBuildExtensionPack.

There seems to a potential relation with the Microsoft UK SDC tasks.

There is some contribution from nFocus and fromfrom Attrice who produce some interesting and reasonably priced tools to work ontop of our build stack. Anyone interested in build management may well want to have a look at their products.