how is there already a test? How do i take it? Do you guys already have the operating system. ?
The same way you signed up and sat for your MCP 70-271 exam. I have Windows Vista Enterprise installed on one of my computers at work.
There are already exam sims from Transcender: http://www.transcender.com/product.aspx?product_id=Cert-70-620
Lots of study material out there, for example: MCTS: Microsoft Windows Vista Client Configuration Study Guide: Exam 70--620
You take the exam the same way as other MS exams, via Vue or Prometric.
Hope this helps