After I wrote my diploma thesis on taxation of virtual currencies in 2007 not much did happen in the virtual worlds. The hype around second life ended soon. But virtual currencies and economies are booming in the gaming/MMORPGs  and  social network area.
In 2010 many US and European Social Networks will adopt the Asian business models. This can become an additonal pillar of their business model, but only if the integrate them right. The Asian culture is completely different to the US one – as you know..

Especially in Asia virtual goods and currencies are state of the art of every social network and mobile apps and games.

Here are some new presentations on social networks and a link list with interesting new articles on this topic.

Papers on virtual currencies & economies

Holistic overview Virtual Currency vendors with screenshots
http://www.virtualcurrencyplatforms.com/facts-and-figures/

Virtual currency on Habbo Hotel
http://virtual-economy.org/files/Lehdonvirta%20et%20al%202009%20Virtual%20Consumerism.pdf

Virtual Economy Research Network – Leading edge research with several papers
http://virtual-economy.org/

Inflation of different MMORPG currencies from  2005- 2008
http://spreadsheets.google.com/pub?key=ttEFy433f0C9bJSczaqGw0A&single=true&gid=0&output=html

Internet & Virtual Worlds in China (40 pages with a lot of facts and figures)
http://www.iftf.org/files/deliverables/SR-1129%20virtual%20china.pdf

40 presentations on virtual currencies, goods and internet in Asia
http://www.slideshare.net/plus8star/presentations

Social Networks in Asia
http://www.slideshare.net/plus8star/social-networkings

Mobile Social Networks
http://assets.en.oreilly.com/1/event/15/Social%20+%20Mobile%20=%20Sociable%20_Social%20Networks%20for%20SMS,%20IM,%20_%20Mobile%20Devices_%20Presentation.pdf

Mobile virtual economies in Asia
http://www.mobilemonday.jp/presentations/plus8star.pdf

Virtual Goods summit