We have just released a hotfix to help identify poor I/O issues on Windows Server 2008 and Windows Server 2008 R2. This is particularly relevant for SQL Server environments as it will the administrator to determine if I/O performance issues are caused by the SAN.
Whilst the output is not particularly easy to consume, it is a good step towards identifying I/O issues.
The knowledge base articles:
Add a fix to improve the logging capabilities of the Storport.sys driver to troubleshoot poor disk I/O performance in Windows Server 2008 R2 http://support.microsoft.com/kb/978000
A hotfix is available that improves the logging capabilities of the Storport.sys driver to troubleshoot poor performance issues for the disk I/O in Windows Server 2008 http://support.microsoft.com/kb/978000
The full details are available here http://blogs.msdn.com/ntdebugging/archive/2010/04/22/etw-storport.aspx