Those are indeed quite helpful, thank you very much. It is still going to be some time before we can patch non-english ESMs but we are working on allowing non-english BSAs. What this means is that you can get audio in German, but all the text will be in English, for now. To do so you MUST have steam and you MUST have the option to download the game in different languages.
Backup your german copy of Fallout3. Call it Fallout3 - German or something.
Open your steam library, right-click on Fallout3 and choose properties.
Click on the languages tab and choose english from the drop box. Click close.
Steam should start downloading an english copy of Fallout3. If it does not, verify the game cache using Steam.
Once the download is done, backup your now english copy of Fallout3 call it Fallout3 - TTW
Restore the german copy of Fallout3 and change the steam Fallout3 language back to german
Copy the German BSA files (all of them) into Fallout3 - TTW
Start the installer, manually change the Fallout3 directory to point to your Fallout3 - TTW folder
Ignore all errors
Install as usual (as per the alpha download page)