Re-released just this morning is the latest Enterprise Vault post 9.0.2 Cumulative Outlook Add-in. Take look at the following technote :
It is only available in English at this time (whereas usually there are multi-languages)
The big change is being able to fully index items in a mixed bitness world (64 bit Windows, 32 bit Office). The other important change that I have seen is the ability to index (or rather re-index) MDC data by WDS.
There is a strong caveat mentioned at the bottom of the technote which is worth looking at. This relates to an issue that was discovered a week or so ago whereby SearchProtocolHost.exe would crash often/repeatedly, after the application of either Office 2010 SP 1, or of Cumulative Microsoft Outlook patches. This is resolved by adding Office 14 to the SYSTEM PATH.