Dude, you totally did get his facial structure down. Right to the face and the pose. It's just all to far awesome to comprehend. Right off the bat anyone would be able to recognize him as Obi Wan, the best Jedi ever next to Windu and Yoda. xD
Definitely agreeing with ~FalconFan - you've captured his likeness beautifully - and seeing as that's the main goal of a caricature, it's very well done. Expression is perfect, pose is familiar, and the whole 'chibi' effect is hilarious. Great work!