The first release candidate of Windows Vista should arrive very soon:
Microsoft is expected to give product reviewers access to Windows Vista Release Candidate 1 (RC1) as soon as Tuesday, and the code looks set to drop publicly as early as Sept. 5. Microsoft has maintained it would have Windows Vista RC1 available by the end of September.
When Microsoft makes available the first release candidate of a product, it means the software is in its final stages of being ready to head to the manufacturer. The goal of making RC1 available is to show testers as close to a final version of the product as possible so Microsoft can identify and get rid of all of the last-minute bugs before putting the product on CDs.