Hi Yana,
I'm happy to announce that we are re-licensing the Wikimedia logos on Commons to CC BY-SA 3.0: https://blog.wikimedia.org/2014/10/24/wikimedia-logos-have-been-freed/ https://blog.wikimedia.org/2014/10/24/wikimedia-logos-have-been-freed/
This is great news - well done. :-)
I would really appreciate your help with replacing the {{Copyright by Wikimedia}} https://commons.wikimedia.org/wiki/Template:Copyright_by_Wikimedia[1] templates on the logos with the {{Wikimedia trademark}} https://commons.wikimedia.org/wiki/Template:Wikimedia_trademark[2] and {{cc-by-sa-3.0}} https://commons.wikimedia.org/wiki/Template:Cc-by-sa-3.0[3] templates.
It might be simplest to change the {{Copyright by Wikimedia}} template so that it just transcludes the trademark template and the CC-BY-SA-3.0 template, e.g. by replacing its code with that at: https://commons.wikimedia.org/wiki/User:Mike_Peel/WMF A better approach, though, would be to update {{Wikimedia trademark}} to make it clear that the Wikimedia logos are CC-BY-SA, but that the rest of the file still needs to have an appropriate free license, and then to simply redirect the copyright template to the trademark template.
Thanks, Mike