Dreadfully underappreciated legend of televised animation. He and his associates (Prescott, Sutherland, et al), set the course for the film/TV industry realizing there was great potential in adapting live action properties for decades, and their model is still going, as seen in the Clone Wars series. Scheimer's productions had heart, and a sluck edge that was lacking in the often corny work of Hanna-Barbera, or the hit and miss work of DePatie-Feeling, Krantz Films, Ruby-Spears, Fred Calvert, et al.
Relevant to this board, Scheimer and his colleagues were undeniably responsible for driving TOS forward with a series that successfully illustrated that there was more to love and expect from that world--beyond the 79 live-action episodes. TAS--and the creative minds behind it--deserve much respect for keeping Star Trek alive.
Scheimer will be missed in this world.