My good friend Joel Semeniuk from Winnipeg has just release the first alpha of his VSTS Process Editor read his post here the tool is on a moderated GotDotNet community.
If you have made ANY customization to the TFS methodologies and edited the xml files by hand well you'll love Joel's tool it's all GUI and you can visually see your work item forms as opposed to have to upload the process and create a new project and see if it worked or not.
I highly recommend it if you plan on doing any kind of Process Template editing.
Cheers,
ET
“It's all good!”