Dear Holger Hartnig,
In regards to your question sent to the Board of Trustees relating to Wikinews's licensure, "attributing to Wikinews" means that you have to credit the text of the article to Wikinews and link to the article. This is similar to the GNU Free Documentation License, only in this case, you only have to cite Wikinews instead of each contributor. The decision to use the Creative Commons Attribution 2.5 License was based on a Board vote, which was influenced by a vote at http://meta.wikimedia.org/wiki/Wikinews/Licensure_Poll, where the community decided on the CC-BY 2.5 license. Other options included the GFDL, the BSD License, the "Wikinews" license and the public domain.
Sincerely, James Hare