unfortunately Lucas has decreed it canon and it is actual considered by LL to be higher canon than all the EU novels, comics and games so no SW authors are allowed to contradict it (they made a new canon level called T canon for the series which is now above C (the EU) and right below G (the movies)) ... there is even talk about them retconing a brand new timeline for the clone wars era once the series is almost over to fix the few continuity errors
hell the last EU novel series even referenced an episode of the Clone wars series... the main villain Abaloth was tied into the Father, daughter and Son from the Clone Wars series...
I'm ok with the series in general except for one thing... and that is *********** Darth Maul coming back with robot legs... seriously *** I really wanna know how Obi-wan is gonna explain that one to Qui-gon's force ghost
Well, if Obi-Wan checked to make sure Maul was dead we wouldn't have that problem now would we? Personally, I like Maul added to TCW because he adds more menace to the series. Maul and Savage have done more with their lightsabers then dooku, asajj, and palpatine combined.