We are now officially done with version 5.01, telling the trust there were some trouble with the MySQL upgrade patch script, which delayed us for about a week, but now development of the Postgresql driver has started.
It will not mean a new AdMentor version, when/if you want the Postgresql functionality it will be available as a separate download. I.e copy a dll, create a database, run a database script, change web.config and you should be able to rock.
We have no exact time limit set for this added functionality, but around 15th June would be my guess right now.