The way I always look at this series is that it is Star Wars and if you are a fan of any and/or all the movies how can you not be interested in viewing brand new stories and characters rolled out to you free of charge? I know some people have a problem and say "but this show is on the cartoon network and if I watch it people will laugh at me." Again I say - it's Star Wars and if you call yourself a fan then you can enjoy the action/drama/comedy and adventure that the Clone Wars delivers.
If it's animation that bothers you then I suppose that nobody here enjoys japanese anime films or shows also? You want to talk about adult content - just watch Ninja Scroll or Ghost in the Shell and then tell me it's just a cartoon. Animation is a an art form - people work hard at SW central to make and develop all these characters for the show - the voice acting is excellent and just because you're not seeing Hayden Christensen or Sam Jackson on your TV doesn't make it any less enjoyable.
Go jump on the official SW forums or the force.net site and see how many adults as well as kids are in SW heaven at having a weekly TV show. I'm a huge SW fan - I could care less if the show is animated or live action. It's top level stories and awesome characters and I'll watch it until they take it off the air.
I'm an adult and I'm proud to say I love watching the Clone Wars!