Some cases can already be conducted in English in Cologne. The FAZ reports:
Deutsche Gerichte verhandeln nun auch auf Englisch

The German Judicature or Court Constitution Act (Gerichtsverfassungsgesetz) provides that the language of the courts is German. There is now an inistiative of the ministers of justice of North-Rhine-Westphalia and Hamburg to have the statute altered, but the Cologne Higher Regional Court (Oberlandesgericht) has already made it possible for civil cases to be heard in English, provided that current law permits it – i.e. for trial, but not in writing. (The regional courts – Landgerichte – in Aachen, Bonn and Cologne, and the Cologne Higher Regional Court have set up particular chambers which can hold an oral hearing in English).

The article has a silly illustration – a photo of a row of very small Langenscheidt dictionaries!

The ministers argue that the most interesting and lucrative cases involving German undertakings are often conducted in US or English courts, at the request of English-speaking business associates, and as a result an English-speaking jurisdiction is chosen at the outset.

This is a bit worrying. There are complaints about how much got lost when there was translation into German, or presumably interpreting in German, and a belief that judges who have worked in international law firms or acquired a foreign LL.M. can speak English. I have no doubt they can, but their ability to write it seems not to be greatly trained abroad. There are a surprising number of German academics and lawyers, educated in English and having spent a year abroad, who write specialist English by translating word-for-word from German.

Brigitte Kamphausen, stellvertretende Vorsitzende des Richterbunds, sagt: „In meinen sieben Jahren als Vorsitzende einer solchen Kammer habe ich oft erlebt, wie durch die Übersetzungen ins Deutsche viele Nuancen und Details verlorengehen.“ Auch für ausländische Kläger und Beklagte wäre es nach ihrer Ansicht angenehmer, wenn sie den Gang der mündlichen Verhandlung „ungefiltert“ verfolgen könnten; den zugrunde liegenden Vertrag hätten sie schließlich auch meist auf Englisch ausgehandelt. Die nötige Sprachkompetenz traut Kamphausen vielen ihrer Kollegen durchaus zu. Denn zunehmend gebe es Richter, die zuvor in einer internationalen Anwaltskanzlei gearbeitet oder einen angelsächsischen Zusatzabschluss als Master of Laws (LL.M.) erworben hätten.

Note also the comments on the FAZ site.