I found the following to be an interesting announcement:
System.Data.OracleClient Update
It looks like Microsoft have decided to deprecate System.Data.OracleClient beginning with the .NET 4.0 release.
Of course, I'm more than a little biased when it comes to anything related to Oracle.
For more information and to download ODP.NET, please see the Oracle Data Provider for .NET center on Oracle Technology Network (OTN).