Have’nt seen any notification’s on the new version and dont know if this is another prerelease or stable but just downloaded and running fine, thank’s avast 
If you were not involved in beta test, then this is the final version. They never release the updates to the masses which are still in beta phase.
This came through the updater, with the pre-release…
I am just updating from 668 to 673…
I was involved in beta test if you read my signiture and very happy for the new pre release.
It’s not a final yet (it’s a release candidate).
http://forum.avast.com/index.php?topic=63151
Final coming very soon.
Thanks
Vlk
Thought so, we are just too eager ;D