According to wikipedia, it falls into T-canon. But following source notes lead to dead links. I have been told by some that it is not canon, and others say it is. Can anyone provide current sources that show it either is or is not canon?
Sadly yes the Cartoon is higher level canon than the novels:
"This is Star Wars, and I don’t make a distinction between [Clone Wars] and the films," Lucas said in an interview released by SciFiNow - a science-fiction enthusiast magazine based in the UK - during last season.
Here is some more reading on the canon.
UPDATE January 2014: Disney will soon be revising the way canon works. There will only be canon and non canon and the intent appears to be to wipe away most of the EU from canon. SOURCE
Star Wars: The Clone Wars series IS NOT CANON. See star wars episode 3, the scene where they meet General Grievous for the FIRST time. During Episode 3 there is also a conversation between Obi-wan and Anakin about padawans that states "Never had a padawan, never will" This 2 factors not only prove the clone wars series canon in doubt, but also ANYTHING AND EVERYTHING created by Disney and other companies.
I'm not a die hard fan, but still, continuity errors piss me off to no end. This extends to Star Trek the new series as well.