Weeeell, everyone should use U... ;-)

You are almost right when it concerns open source and the here and now (as many OS and script languages are not yet utf8-ready, perl and linux are exceptions AFAIK). But remember that a lot of software is written in other languages without any intention or need for worldwide collaborative development. Why should its programmers jump through loops just to print a message in their native language?

From a practicability standpoint using utf-8 now might lead to problems. But from the standpoint of non-english-speaking people it is high time that utf8 is in universal use.

And hopefully those problems lead to faster adoption of utf8 instead of the practical solution. Because otherwise we get the same situation as with IPv4 and IPv6. The intertia of the ones with enough IP-addresses prolong the problems of those with too few.