As of today (09th November 2009) Oracle 11g Release 2 is available for Solaris SPARC.
You can download it from OTN.
The release includes database, client and grid infrastructure (aka “clusterware” as well).
According to the release schedule Oracle 11g Release 2 for Solaris INTEL is most likely to be released next. Windows is scheduled for the second quarter in 2010. See my previous post for more information about possible release dates.