Which File system Hierarchy Standard Does Ubuntu 12.04 Using ? & What are the changes ?
On wikipedia the latest version is v3.0 (2012-07-01)
The current version is still 2.3 (2004) and Ubuntu, like Debian, is based on that. At the Linux Foundation it is noted that
They aimed to release it by 1 July this year as this article describes, so the date you saw on wikipedia was merely this date they had earmarked. It hasn't actually been released yet at the time I am writing (12 September 2012). The changes haven't been decided fully, but there are some useful links in the link above (such as the fhs mailing-lists discussion and there is a discussion at lwn.net.
More details on the existing specifications are available at the Linux Foundation.
For more general information, two great questions on this site explain the filesystem hierarchy well:
Ubuntu will most probably inherit the Debian FHS standard as mentioned in The Ubuntu-Policy also locally available under /var/share/doc/ubuntu-policy/fhs provided you install ubuntu-policy package to see the implemented File System in Ubuntu.
If you are concerned with what does Ubuntu Implements of Standard FHS 2.3 and changes or makes exception to it , to integrate itself within it .