Task force/China/Interview (surveys) with Chinese bloggers/Comparative Advantages
When I did the editorial work for TEDtoChina, I often searched the background of the speakers, and often reach their page in English Wikipedia, while the corresponding Chinese Wikipedia page, sometimes it is missing, or sometimes lacking of content.
I think, the advantages of Wikipedia are their brands, the content from the English Wikipedia, the community culture and the sprite of volunteer-ism and non-profit. All these are unique asserts for Wikipedia comparing with Hudong and Baidu. Hudong and Baidu may be more popular in page views or brandings, but they lack credibilities.
Meanwhile, the editing model for Hudong and Baidu are not accumulate knowledge systematically, but simply copy-paste materials. This will impact the quality and credibility of the content.
For high-quality content in English language on the Net is far richer than these in Chinese language, Wikipedia may grasp this chance.
I have both used Baidu and Hudong. These two lack the control of contents, so you will see a lot of contents are copied from copyrighted sources by users. Hudong enlarged the effort to spread recently, adding entertainment and hotspot contents. However, since Baidu is the most-used search engings, Baidu increases the rank of the content of Baidu itself, it's not good for any third-party online encyclopedia. Besides, because of the competition between Baidu and Wikipedia, Wikipedia articles cannot get a better rank in Baidu. Type "毛泽东” (Maozedong) in Google and Baidu, and you will find out that the Wikipedia article of Mao is in the second page of Baidu, but the first result of Google. It has a big influence on the users.
I have used all of these. Compared with others, it is obvious that Wikipedia articles have more aspects, and have a higher quality, especially in some uncommon or professional areas. Maybe Wikipedia's promotion are worse than Baidu and Hudong, but it has a more professional brand image.