There is a tendency to leave NATURAL-ADABAS and going toward COBOL-DB2. The reason is mainly financial.
Personally, NATURAL-ADABAS is my "first love". I still believe that they are among the best development infractructure ever existed, and that they were designed from a programmer point-of-view. I still think that ADABAS is the closest database to the definition of "prefect". From time to time I still play with NATURAL and ADABAS, just to remember the good old days. However, it is proven that more and more companies are moving to DB2.