TV has Spinoff Fever. “The Office” and “Family Guy” have new shows launching next season. “House” and “Prison Break” are creating potential spinoff characters. Now there’s word that “Gossip Girl” may multiply. The CW show’s creators are planning a spinoff series set at a girls boarding school, according to The Hollywood Reporter. Producers want to give co-star Taylor Momsen (Jenny) her own series or introduce a new character in the fall who is later spun off.