I went through the installation of [64-bit ODAC 11.2 Release 5 (220.127.116.11.20) for Windows x64|http://www.oracle.com/technetwork/database/windows/downloads/index-090165.html] and 32-bit Oracle Developer Tools for Visual Studio download yesterday. I ensured I installed in separate base directories.
I can connect to my desired schema using Visual Studio (add a server connection ) and also in SQLDeveloper 64-bit. Ok, Since I am working against SharePoint 2010 then I will be restricted to the .NET 2 versions of ODP.NET as .NET 4 is not supported.
I am however, I bit surprised not to see the *.NET 4* versions of Oracle.DataAcess in the GAC (c:\windows\assembly) as well as the 32-bit and 64-bit .NET 2 versions I can see currently. I am thinking I could need these for my non-SharePoint development.