Yes, Microsoft is getting quite a reputation for abandoning or deprecating it's data access products/libraries. One thing you can do is download a 3rd party product called dotConnect by DevArt. The express edition is free.
... however, if you are working in a shop that doesn't like its development team to use not well known third party tools, there's an alternative--but it still requires that you go to a non-microsoft source. Use Oracle.DataAccess.dll with the Oracle Data Provider .NET (ODP.NET) client installed. This can be found on Oracle's website:
For now, System.Data.OracleClient still works, however Microsoft's deprecation message on compile is a warning to you that the feature will eventually be phased out completely--and although works, may not actually be supported.