When I was really young (age 9 - 14) i did nothing but gymnastics for 9 - 12 hours a week. Gymnastics teaches the body how to adapt and move in the most unlikely ways. It taught me a great knowledge of where my center was.
What it gave me, was the ability to learn almost any new movement quickly.
When I started Aikido when i was 17, I improved extremely quickly getting my 5th in 4th kyu in less than "standard" minimal time.
It seems that the arts that teach >movement< in general rather than "martial movement" like in karate or jiujutsu, give the best foundation for learning new arts, whether they be martial, or dance.