Faction Change not available yet in Europe
It is standard policy for us to not announce specific dates for this kind of service or for things like patches. It isn't an EU thing, it is a Blizzard thing. We are not leaving you "in the dark" without good reason, and the reason is not the one you suggest. One of the reasons is simply because we do not want to raise expectations and then squash them again. Experience has shown us that doing that is actually much worse.
Having said that, the release of this much awaited service in the US does implicitly raise excitement and expectations, and this is quite clearly evident by the popularity of this thread today.
Faction Change ETA in Europe
Here we go: it is not coming today, tomorrow or this week, or probably next. However, plans can change though, but this reply should give you a much better idea of when it is probably coming and should help you to better plan in advance, should you wish to do so.