The turnover of talent on Channel 9's 10 p.m. newscast has been enormous. With the retirement of Ed Sardella, the ship-jumping of Mike Nelson and the ignominious removal of sports hunk Tony Zarrella, only anchor Adele Arakawa remains from the crew that had attracted large audiences for years, and her new counterpart, Bob Kendrick, isn't exactly Mr. Charisma. But Roger Ogden, the station's president and general manager, came up with a surefire way to compensate, bringing up weathercaster Kathy Sabine and sportscaster Drew Soicher from the outlet's ultra-successful morning show. Thanks to their presence, the newscast has been revitalized -- much to the chagrin of its competitors.