Last week, we upgraded a smaller Reporting Services project from SQL Server 2000 to SQL Server 2005. It went without any problems and actually also solved a couple of issues we had with the old version. One nice new feature that we immediately used was the possibility to hide the prompting of some of the parameters. Another small enhancement that was obvious directly was the fact that there is a small calendar next to date parameter fields. The SQL Server 2000 version only supported textboxes and comboboxes.