I just received an email from the Development team explaining the detailed dates when what version of OBIEE will be in what stage of Support. So again for all readers who have not had the chance to look at the  lifetime Support policy from Oracle, I'll  try to explain this in easy words:

Examples:

11.1.1.5.0 was released in May 2011. 
=> So 11.1.1.3.0 (the version before that) went out of patching support ( or "error correction support" ) 12 months after that, i.e. June 2012.

Note here:
It went out of error correction support, which means Development will not fix bugs, or issue patches after that.
The product can still be supported by Technical Support ( as "best effort support" ).
So - Questions will still be answered, but there will not be fixes to bugs or glitches.

11.1.1.6.0 was released in February 2012. 
=> Therefore 11.1.1.5.0 will be out of patching support / error correction support starting March 2013.

I hope this clears up some of the questions/concerns that you might have had.

Oh, and of course to mention the latest and recommended version to use: 11.1.1.6.0 + 11.1.1.6.5 bundle patch is "just what the doctor ordered".