The official World of Warcraft EU site is reporting that they have opened the downloader service for the European final beta phase. The official word is below:
In preparation for the start of the Final Beta, you can start downloading the game installer in your preferred choice of language (English, French or German), using the links below. As a reminder, the first phase of the Final Beta will be opened to those who attained an authentication key through the official Blizzard pre-order campaign, as well as current Closed Beta testers, who will maintain their existing account and characters. More testers will be included in the near future.
You do not need to download the file if you already have the latest version of the client software installed. This download is intended primarily for new players entering World of Warcraft for the first time.