Robots Exclusion Protocol Posted on June 4th, 2008

On 3rd June 2008, Google, Microsoft and Yahoo have announced a collaboration to support robots.txt and robot Meta tags. By the end of June 2008, Microsoft will be supporting wildcard * and the ALLOW directive in robots.txt file.
For more information, please visit the links below:

Microsoft Live Seach Webmaster Blog
Google Webmaster Central Blog
Yahoo! Search Blog