Utada Hikaru and Ayu collaboration?

[PrincessAyu]

I was reading Utada Hikaru info on wikipedia and came across this bit:

Rivalry

Utada Hikaru is commonly considered to be the direct rival of J-pop star, Ayumi Hamasaki, which caused intense debate between fans of both artists.

On March 28, 2001, Utada Hikaru and Ayumi Hamasaki came in direct competition. Utada's album Distance and Hamasaki's album A Best were released on the same day. Distance topped the charts for the first week while A Best was #2. The following week A Best hit #1 and Distance dropped to #3. At the end of the year, Distance and A Best were the top two highest selling albums of the year.

In an interview with Japanese TV station NTV, Ayumi Hamasaki explained that this rivalry made her feel terrible, but it was pushed by the record companies.[4] In protest, Ayumi Hamasaki, who has a very large degree of creative freedom, is depicted with a tear on her cheek on the cover of her A Best album. It is speculated that this protest is also the reason why she insisted on re-recording some of her old tracks that is featured on this album.

Then I saw this video on youtube. Utada and Ayu seemed to have a nice time and get along well, however I have no clue what it was about.

I think they both have a nice voice... anyway I'm wondering, what do you think, would Utada and Ayu ever collaborate? Cause they were said to be rivals, yet Ayu says the whole rivalry thing had been pushed by the record companies, and they seemed to get along fine on MS. So would this be a possibility in the future?

(Unless they already sang together once before, or Utada visited Ayuready? but I think she didn't...)