A few days ago, Deutsche Bahn opened parts of their timetable data. However, the schedule is published in a proprietary format and can only be accessed through an API. Because the data consists of static timetable data, it would have been reasonable to publish it as a GTFS feed.
Fortunately, it is possible to create a GTFS feed from the API :)
For testing, you can download a GTFS feed for the DB long distance lines (valid from April 1rst to Juni 30st 2016) here.
The feed is updated regularly.
The python script used for the conversion can be found on github. It's a quirky sunday evening hack and comes with absolutely no guarantees :)