Understanding the new style Team Build under TFS 2010

I found this series of posts about customising Team Build 2010 from Ewald Hofman:

http://www.ewaldhofman.nl/?tag=/build+2010+customization

Now I am beginning to understand how the new style Team Build works - thanks Ewald.

I have a very clear idea of what I want to achieve with my Customised Builds:

• Produce output that is targeted at multiple Environments (e.g. Function Test, Live etc)
  • This will mean using a Build Configuration file containing the configuration values required for each Target Environment. I already have this kind of file that I used under Team Build 2008: each Environment Section contains one or more Project Sections, and each of these contain replacement configuration settings for one or more project config files (i.e. App.config, web.config, etc).
  • Each Build definition will select the Target Environment(s) and Project(s)  relevant to that Build.
  • For each Environment, Custom Activities will:
    • Read the settings from the Build Configuration file mentioned above,
    • Amend the relevant  project configuration file with the required settings,
    • Compile the project (or Publish, is it's for a ClickOnce Deployment),
    • Replace the amended project configuration file with the latest version (so the next Environment has a 'virgin' version).

• Give each Environment/Project combination a version number
  • I managed to do this for ClickOnce output under Team Build 2008 and I want to extend  this to other types of output - websites, web services etc.
  • I would also like to use this version number for our Assemblies and Ewald Hofman has a great example for doing this here:  http://www.ewaldhofman.nl/post/2010/05/13/Customize-Team-Build-2010-e28093-Part-5-Increase-AssemblyVersion.aspx.