SERIES PREMIERE: Keith Olbermann, who co-hosted ESPN’s SportsCenter for a memorable stretch beginning in 1992, returns to the ESPN family two decades later with a new sports show, premiering tonight on sister network ESPN2 right after prime time on the east coast. One thing about Olbermann – well, make that two things. One, he’s always smart. Two, no matter his chosen show or topic, he’s always watchable, so expect to be entertained. Welcome back, Keith.