Audit Vault is very much in active development, and has been having regular updates. The last one was version 10.3, and came out in December of 2011. Given that the version number is still 10.3, the name hasn't changed to 11g yet.
I'm not sure I understand the issue. Database Vault is an option of the Oracle database. When the Oracle database changes version to 11+g+, or 11+g+R2, so do its features, including Database Vault. Audit Vault, on the other hand, is a stand-alone solution. It follows its own numbering scheme independent from the database. In that respect, it is like the eBusiness Suite, which is at R12 even though the database is not.