Courtesy of the Wrestling-Online newsletter, the Haku situation is solved:

FORMER FEDERATION SUPERSTAR RETURNS

- Just last week, WCW awarded him the Hardcore title. One week later, he finds himself participating as one of the mystery superstars in the 30 man Royal Rumble. The artist now formerly known as Meng is back in the WWF, still using his WWF name, Haku. According to a story on WWF.COM, Jim Ross contacted the man from Tonga to return to the WWF on Wednesday. He was wrestling for WCW without a contract, thus allowing him to jump ship any time he wanted. Haku didn't hesitate to accept the offer - as well as the contract. He was supposed to wrestle for WCW on Saturday night, but gave his Hardcore title to the Barbarian so he can give it back to WCW officials. Haku packed his bags and went to New Orleans. One thing the article outlined is that Haku is here, and here to stay.