Trivia: When Asajj Ventris is reporting to Count Dooku for the second time and says she will redouble her efforts to find Anakin, Dooku says, "I hope so, for your sake - " He is then cut off. This line connects with part of a conversation in episode 6 of the TV show.
Trivia: At the monastery on Teth, a Clone Trooper is hit when an AT-TE cockpit explodes from the just-arrived Separatist Droid Army's fire. When the Trooper is hit, he yells the Wilhelm scream.
Answer: Canon in the Star Wars universe is a somewhat complex term as it has several levels ordered in a hierarchy of precedence. Facts stated at a certain level are considered as canon, unless contradicted by something at a higher level of canonicity. The uppermost level of canonicity are the six live-action films. Lucas has stated that the television episodes (which include the Clone Wars movie, which can be considered as the first episodes of the TV series) are to be considered as the next level down in canonicity, so below the films, but above any other releases (books, comics and so forth). So, basically, yes, they're to be considered canon, except in any case where they contradict something established in the live-action films.
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