Short answer: They're not ready for prime time quite yet.
Longer answer: We've been following this topic over in the Asia Pacific forum for several years now. Here's one of our earlier threads: Native Language Domain Names News [webmasterworld.com]. The entire native domain name market hasn't evolved much since 2000. In order to get these names to work basically either everyone's browser needs a plug-in that supports this naming scheme, or server software world-wide requires some extension.
Every year we hear grand announcements about how native domain names are just around the corner...and I've not got much confidence that this will happen anytime soon. (Although it still sounds like a great idea to me.)
however, what I have not read/heard anywhere till today is about the compatibility of google and other search engines with domains names in languages other than English. I spoke to the customer care(or whatever they are called) in google and they termed it as "confidential information" and so can't say. Very surprising.
Sorry
