I know this is going to upset quite a few people and it will cause a bit of pain. Eric Has posted this on MSDN Blogs. As you may be aware MSDE is coming to the end of its support lifecycle. It will not be supported on windows Vista. As a replacement SQL Express has been released this is also free to download, deploy and redistribute.
Using SQL Express gives you several benefits over MSDE. See this link to the upgrade site for a full list of features. Some of the differences are a maximum database size of 4GB, removal of the workload governor, a free integrated management tool, SQL Server 2005 Reporting Services then there are a whole host of other features please see the white paper.
The two areas I think will upset you are some of the parts that are missing from SQL Express which are the SQL Agent service and the DTS run time. The DTS runtime can be downloaded and installed along side SQL Express. However to get around the SQL Agent you can use Windows built in task scheduler in combination with the SQLCMD tool to execute system maintenance jobs like database backups and other database access jobs.
Just to follow up on my post MSDE nearing End of Life - No MSDE Support on Vista and from Eric’s post....