I just discovered that Collins Dictionaries and Langenscheidt have been collaborating since last autumn and a new edition of the big one-volume Collins dictionary is to be published in the UK on May 4th 2004 and in Germany apparently in April. This will be the fifth edition.
Collins Dictionaries is now part of Harper Collins, but it was a different Mr. Collins who started the dictionaries, in Glasgow in the 19th century. 20,000 new words, price £30 in the UK and 54,00 or 59,00 (with thumb index) in Germany.
Thanks to Susan Siewert for the information. No news as to a CD-ROM version. As mentioned earlier, Pons, with whom Collins Dictionaries used to collaborate, brought out a Großwörterbuch which it developed itself (I believe on the basis of Collins).