Query Optimization in SQL Server 2005

With the hosting of the CLR within SQL Server 2005, as well as the support for more data mining algorithm, it would be interesting to understand in-depth about what kindof statistics are collected by SQL Server 2005 to support query optimization.

Check out
http://www.microsoft.com/technet/prodtechnol/sql/2005/qrystats.mspx

Also, another interesting site to watch is Ian Jose's weblog. He is one of the folks working on the query optimizer.