I guess one of the first questions should be; "Is some partitioning of the
Internet community such a bad thing?". Why should it matter if, say,
Chinese-based domains aimed at Chinese audiences are not meaningfully
accessible to non-Chinese Internet users?
There's a distinct issue that exists apart from the inter-human aspects -
the packets containing these new character forms will flow, at least
occasionally, into pretty much everyone's machines, routers, NATs,
firewalls, web caches, etc - all of which need to be able to handle these
new packets without ill effects. (The definition of "ill effect" will
vary depending on what the box is supposed to be doing.)
For instance, it would be "a bad thing" if some "transparent" web cache in
some ISP went south when it re-resolved a URL that contained a domain name
that either had itself a label in some non-hostname character set or was
resolved via a CNAME containing non-hostname characters.
In other words, although the humans (and their user interfaces) may
Balkanize, the infrastructure on which the net operates should not.
--karl--