As pointed out in the main link, ICANN has nothing to do with the testbed. NSI Registry (not the registrar) decided to do it because, if the IETF makes this available, it would be nice of the registrars in com/net/org were able to register the names. There are already other testbeds run by other (less newsy) groups of people; you can even set up your own. It's not that big of a deal.
And it's "non-ASCII", not "non-English". There are already plenty of domain names that are non-English, as others have pointed out already. ASCII is a character set (of sorts); English is a human language. The differences are defined in detail in the requirements document for the IETF's working group.
Full details on the working group can be found at http://www.i-d-n.net. Maybe folks should consider reading the copious archives before declaring that it can't be done. It can be done, and hopefully it can be done right. We're quite sure that the Powers That Be in the IETF won't allow it to become a standard if it isn't right.