The German translation of "Win with the London System" is now available with the title "Gewinnen mit dem Londoner System". I still have not got the book myself but expect some copies to arrive in the mailbox any day now. It will be a nice addition to my book shelf and even if my preferred reading language is English, I suppose I will read it from cover to cover just to get an impression of the translation.
As for the content I know that there are no new analysis or variations. Three minor misprints in the English edition has been corrected - that's all. It obviously would have been possible to improve the analysis and add some recent games with relatively little effort. Yet I believe this was a wise decision by Gambit Publications. Partly because the London System is a low-maintenance system which generally doesn't require heavy loads of analysis and memorization but mostly for marketing reasons.
I know that original German works which are later translated to English and updated in the process have caused a lot of frustration for German buyers who feel cheated when they have to buy a new book in order to feel fully prepared. Moreover the two publishing companies Quality Chess (their books are better than their website) and Chess Stars which have made it a habit to publish revised versions of their books have mainly gotten criticism for their efforts. One example of the typical reader reactions can be found at the ChessPublishing discussion forum (as far as I know the best chess discussion forum on the net).
The first review (in German) of this German edition can be found at Freechess Info . This, by the way, is an excellent review site for those who can work their way through a German text. At times I find their verdicts too kind, but the reviews are generally well written and well researched. I don't expect there to be a lot of reviews in English for this translation.