Creative Commons 4.0

[MuwuM]

Creative Commons 4.0 are out for some time now. I personally think we should update our licenses.

Why should I use the latest version of the Creative Commons licenses?
The latest version of the Creative Commons licenses is version 4.0. You should always use the latest version of the Creative Commons licenses in order to take advantage of the many improvements described on the license versions page. In particular, 4.0 is meant to be better suited to international use, and use in many different contexts, including sharing data.
see official CC homepage

[titi]

Do you know something about the possibility to release CC-BY-SA V3 stuff as CC-BY-SA V4 ?
Is CC a generic license regarding new versions?

If not.... no way, we are not able to relicense the work of other people.

[MuwuM]

Yes and no. No CC is version-dependent. But, CC-BY-SA 2.X (and later) can be reused under later CC-BY-SA versions.

Compatibility mechanism in BY-SA licenses
Under the 4.0 licenses, licensees may use licenses designated by CC as compatible for their contributions to adapted material.

The ShareAlike licenses require that licensees make their contributions to adapted material available under the same terms and conditions, or, where the license allows, under a license designated by CC as compatible. The version 1.0 ShareAlike licenses require that adaptations be made under exactly the same license as applied to the original work. Starting with the release of the 2.x license suites, CC expanded compatibility by allowing contributions to adapted material to be created under the same or later version of the original license, including other ported versions of the same or later version of the license. The 3.0 Attribution-ShareAlike goes one step further, by allowing those contributions to be licensed under under a “Creative Commons Compatible License,” defined to mean licenses approved by CC as essentially equivalent to the 3.0 Attribution-ShareAlike license.

To date, CC has not approved any other licenses as compatible. However, CC will develop a compatibility process shortly following launch of the 4.0 licenses, and begin evaluating other licenses. You can view the list of compatible licenses, and a post about the upcoming compatibility process. You may also want to review CC’s statement of intent for the Attribution-ShareAlike licenses, and a draft statement that sets out further principles for the ShareAlike licenses. [source]