There was a very interesting interview and article on the DB night trains in Monocle in February: http://www.monocle.com/sections/busi...sell---Berlin/ (subscription required, I bought the paper magazine)

And generally have to agree to Tyler Brule's opinion that a sort of "arrivals lounge" would be very welcome to justify current DB train pricing compared to flying. Let's say a few showers installed at each major German DB lounge exclusively for CNL travellers and a deli breakfast box against the higher fare CNL ticket would do fine.

The best service for night trains currently might be in either China or Russia if one pays for the better cabins. Food on board is also substantially better there most of the times. DB has some catching up to do if CNL is to became the European standard.