Tech pundit John Gruber threw in the towel on his domain ✪df.ws.
He writes:
What I didn’t foresee was the tremendous amount of software out there that does not properly parse non-ASCII characters in URLs, particularly IDN domain names. Twitter clients (including, seemingly, every app written using Adobe AIR, which includes some very popular Twitter clients), web browsers (including Firefox), and, for a few months, even the Twitter.com website wasn’t properly identifying DF’s short URLs as links.
Worse, some — but, oddly, not all — of AT&T’s DNS servers for 3G wireless clients choke on IDN domains. This meant that even if you were using a Twitter client that properly supports IDN domains, these links stillwouldn’t work if your 3G connection was routing through one of AT&T’s buggy DNS servers.
There is still a lot of heavy lifting left to do among many software and hardware vendors before IDNs can go mainstream. Unless, of course, a country — say Russia or China — mandates their support and pushes the vendors along.
PS: I’ve updated my top-level IDN tracker.