According to Niconico Douga, Tezuka Production has announced the eleventh OVA of Black Jack
. It will be the final volume of the OVA series. A live voice recording session of the OVA will be streamed on Niconico Live on May 14th.
The OVA series had been released from 1993 - 2000 and the late Dezaki Osamu
had directed the whole series. It's unknown if Dezaki was involved in the new OVA.
Source: Niconico Live