Grouping Sets

Hi hackers (and specially Pavel Stehule),I could really use the grouping set feature for some complex queries
I'mmigratingfrom other db vendor. If my WEB searching is precise, thiswiki page [1] and this thread[2] are the last
updateson the subject. I'm willing to test how these functions in my project but some questions first: 1- is there an
up-to-dateversion of the patch that I should be aware of? 2- Can I apply that patch to 8.4.8? 3- any extra
recommendations? 
 

TIA,
Mariano

[1] http://wiki.postgresql.org/wiki/Grouping_Sets
[2] http://archives.postgresql.org/pgsql-hackers/2010-08/msg00647.php