Actually that is Huang Q. There is her trademark move Huang piro in the beginning. In the end you could clearly see her face and clearly that is Huang not Wu.
I don't know which site you are referring to but here is the official list from FIGhttp://figfront.lx2.sportcentric.com/system/files/2677/original/Nominative_Paris_16.03.2011pdf.pdf?1300280305China has 5 girls competing. Normally you can only have up to 4 but the new rule allow more than 4 if the nation qualified under the new World Cup A rule.
I am so impressed with He Kexin's bars. She's improved her handstands and is really nailing the important ones during her pirouettes. And thank baby jesus she got rid of that dead hang after the toe shoot! Very very excited for this competition. Worlds looks to be pretty interesting also. :)