Has anyone been able to get the nexus s into card emulation mode?
The latest android release does not seem to support this yet.
This article says it's possible http://www.nearfieldcommunicationsworld.com/2011/02/13/35913/uncovered-the-hidden-nfc-potential-of-the-google-nexus-s-and-the-nokia-c7/
Long story short:
Yes, it's possible, but only if you hack. The article you've posted shows how it's done.
Such a hack will only work with the Nexus-S, and only on modified phones with android 2.3.3 Everything relies on undocumented framework classes that may change anytime.
With the official android SDK it is not possible.