The Yale School of Drama and its Repertory Theater have a special niche in American theater. So when Yale hired away the artistic director of Baltimore's Center Stage as dean and artistic director of the two organizations, it spoke monologues about the commanding place of regional theater, rather than Broadway, in artistic life today.

Stan Wojewodski Jr. had a powerful impact in his 13 years as artistic director of Center Stage and helped make its occupation of first-class quarters on Calvert Street a success. He will leave just after completion of its expansion into the Head Theater, a second performing space he wanted. At Yale he will have an administrative burden that he may have been spared here by Peter Culman's role as Center Stage's managing director.

Center Stage is a strong institution and was never a one-man show. Irene Lewis, who has directed outstanding productions there, has been named acting artistic director for the 1991-92 season. The search for a permanent replacement should find many strong applicants, thanks to the eminence to which Mr. Culman and Mr. Wojewodski have guided Center Stage.