Thanks for starting this thread. It's cool to hear thinking about Wikimania 2013 speaker options early on. I really like the categories Andrew proposed, and I think it will help clarify the thinking around what different speakers can bring to the table.
1. Ray Chan, 9gag. Certainly 9gag has made a splash in the geekier Internet community, but it would be good to see what he'd want to talk about first and whether it had any relevance to Wikipedians and free culture. Important to remember: Wikimania is first and foremost a community event, not just a great speaker series.
In addition to what Andrew said...
To be totally honest: 9gag is viewed by many Internet communities, such as Reddit and 4chan, as a leech which contributes very little to these communities. There are often rules that explicitly disallow use of 9gag stuff on some of these sites. I don't think we necessarily want to align ourselves with 9gag, and I don't think they would have much of substance to say about how read online community is formed or operates.
If we want a general meme-ery speaker, Chris Poole of 4chan and Canvas fame would be fantastic, though like Andrew said, the direct connection is somewhat tenuous.
2. Charles Mok, certainly relevant to the conference, but not sure how exciting a speaker he is.
3. Arianna Huffington. Not really a fan of this pick. Can get quite political, and not obvious the overlap between her site and free culture.
+1. Too American-centric, too political.
4. Thomas Crampton is a good pick. He was a respected working journalist and may be able to set the table on what Wikipedia and free culture mean across Asia.
5. Don't know much about Ada Wong.
That said, how about some other ideas:
1. Joi Ito. He's a great friend of Wikipedia, and spoke in 2007 Wikimania in Taiwan. He's now MIT Media Lab director, and could give great Asia perspectives.
Joi also has a strong free culture perspective. I think as far as someone who can balance a global and regional perspective, he's a great pick.
Maybe a wiki page about the options would be a good place to store a list for consideration?