One of our strongest early adopters in the UK has been Conchango - with a special focus on the replacement for DTS, Integration Services. They have produced an extremely good paper which compares SSIS with Informatica. I would recommend it as a bed time read even if you are not interested in Informatica and just wish to understand SSIS in more detail and where it sits in the ETL market space. Well done Conchango!

Doh! Forgot the link - here it is http://www.microsoft.com/sql/integration/Conchango.mspx. Apologies all!