"Do the Kings want Yao Ming and his expiring contract?

No, they don't.

As reported by the Houston Chronicle, the Houston Rockets are looking for a team willing to take on Yao, who is out for the season with a stress fracture, and expiring contract in exchange for young talent and draft picks. The Rockets have an insurance policy to cover most of Yao's salary ($17.7 million) and a trade exception worth $6.33 million to entice teams."