It’s a busy week, the very shank of the May sweeps period. (You can tell by all the perils-of-Pauline movies.) But it’s all a postscript to the 1991-92 TV season, which is officially over. Time to appoint the guest star of the year. The runners-up were Martin Mull—for Parker Lewis Can’t Lose!, Dream On and his recurring role on Roseanne—and Ken Howard for The Golden Girls and P.S.I. Luv U. Even if you saw Howard, you might not have known it was he. The heavier, less hirsute Ken is virtually unrecognizable from his White Shadow days. And the winner…Joanna Cassidy, who turned in solid work in a number of not-always-good TV movies and minis (Grass Roots, Taking Back My Life and Live! From Death Row). As a series guest star, she went from the sublime to the ludicrous, playing ex-wives on both Northern Exposure (to a recently deceased buddy of Maurice’s and Holling’s) and on Drexell’s Class (to star Dabney Coleman, her former Buffalo Bill cohort).