There is a comparison table that can be found here:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnsse/html/sseoverview.asp

The SSE Home Page is here:

http://lab.msdn.microsoft.com/express/sql/

>Is there a big difference between MSDE and SQL Server Express? Can I easily replace MSDE with SQL Server Express once it's release version is available? Any comments or links related to this is welcome.
>
>Thanks,
>Einar
>
>>You may distribute MSDE. Keep in mind that Express is currently in beta. I would not be distributing it until release later this year.
>>
>>>I have been considering to deploy VFP applications running on MSDE or SQL Server Express. May we use those data engines for commercial purposes (keeping in mind its limits) or for development only ?
>>>
>>>
>>>Thanks,
>>>
>>>Juan C.