Identifying SQL Server 2005 Enterprise Edition features in Use

Hi all,

recently I need to downgrade from SQL 2005 Enterprise version to SQL 2008 Standard version.
is there any way to keep trace any enterprise features is using?

in 2008, we able to use the script as below:

SELECT * FROM sys.dm_db_persisted_sku_features

1) how to identify all the Enterprise features is using by SQL 2005?

2) able downgrade from SQL 2005 Enterprise version to SQL 2008 Standard version?