I just noticed that 11gR2 (188.8.131.52+) is now certified for use with Oracle Fusion Middleware 11g. A few weeks ago I tried to install Fusion on a 11gR2 database but I encountered issues. Since it wasn't certified I rolled back and installed 11gR1.
The problem I had at the time was that the Single-Signon Repository Creation Utility errored out with , "The database does not contain Ultra Search Schemas WKSYS and or WKPROXY. Please install them and try again."
It appears Ultra search has been desupported in 11gR2: http://download.oracle.com/docs/cd/E11882_01/readmes.112/e11015/toc.htm#BABBFCCH
I just did a quick search on Metalink and looked at the release notes but I don't see any updates as to how to get around this problem. If you have installed FMW11g on 11gR2 and you found a solution or if you didn't hit this problem please leave a comment.