Development of Creative Commons licenses

["Ivo Emanuel Gonçalves" <justivo AT gmail.com>]

Saluton,

There's a few people here aware that Xiph's working on the community
portal Spread Open Media[1].  We require that all contributions to the
project be licensed under CC-BY 3.0.

Recently, an outsider proposed that it was perhaps better if we
required that contributions be under "Creative Commons Attribution
License 3.0 or any later version published by Creative Commons".
Something akin to what some GPLv2 projects do.

I actually like this approach, as it would allow us to easily upgrade
to newer versions of the license without having to track every
contributor to get the permission to do so.  However, I'm not sure if
this is legally allowed by the CC licenses.

Advice appreciated.

-Ivo

[1] //spreadopenmedia.org