Microsoft has announced that System.Data.OracleClient will be available in the upcoming 4.0 release of .NET Framework; however, it will be marked as deprecated.
This will have no impact to existing applications and these applications will continue to work as expected. Developing new applications which use OracleClient will be supported; however, warnings will be raised if the applications are compiled against .Net 4.0. Once compiled, no warnings or errors will be generated while running these applications.
Microsoft strongly recommends that customers use partners’ ADO.NET Provider for Oracle instead of continuing to use Microsoft’s OracleClient for new application development.
Microsoft will continue to provide hotfixes for critical issues in OracleClient as per the standard support policy for .NET Framework 4.0. Microsoft will also continue to make critical bug fixes in future service packs for .Net Framework 4.0.