I'd add to the voices on this one (although I am usually quiet on places like this).
IMHO, a separate set of Euro servers accessible only by Euro clients is a very bad idea. There are plenty of European people playing across the current stack of servers, if player load is an issue why not just add a few more servers in that are accessible to anyone.
From a software development point of view, why would you want two sets of code to maintain for what should be the same product, code can be regionalised without having to resort to a separate client for those people in Europe.
It would be interesting to see what the current localisation split is across the current live stack.
