This change has been implemented due a problem/limitation on non SQL OLEDB that generated invalid packages when using wizard, this problem has been reported by many customers so a new topic will be added on books online to mention this restriction.

However using advanced editor is still possible to select non-SQL OLEDB providers since mappings need to be manually specified and that way the problem wouldn’t happen since mappings need to be manually specified.

There are some public alternatives using custom data flow components  that might be a good alternative  http://www.codeplex.com/kimballscd, this one can be deployed on SQL 2005 /SQL 2008 any case problem mentioned above still persist but only happens for specific OLEDB commands.