I loved the song too. I don't hear it nowadays, though. It's out of time. Most of the songs of Shakira have the same feature, they keep on ringing on your head for some while. She looks sexy on every video. Have you checked out the video of her new song "Rabiosa"? She is pole dancing on this one. And she has changed her hairdo as well. Sexy.
And no, I don't know the meaning of wakawaka, do you?