Its still listed as a TODO for Aria 2.0 on the Aria FAQ on the KB (the current 1.5 version has been out at least 2 years and a half ago).
Unfortunately i believe that Aria hasnt got enough "interest" from the users which made it a lesser priority compared to other parts of the projects.
A Monty comment of March 2014 on MDEV-5649 :
With the current version if Aria INSERT and SELECT works concurrently but UPDATE and DELETE needs a table lock.
We never had the time to remove the table lock for Aria with UPDATE/DELETE as we have focused all efforts on developing MariaDB.
hi guys, anyone know about this mdev?