There are two caveats: nobody can tell the future of human cultural history or any individual legal organization, and while the repository and wikis as a whole, and virtually all legally hostable media of genuine value, are preserved indefinitely, obviously no guarantee can be given concerning any specific individual image or article.
Beyond that, the best guarantee is the license it's under. The Foundation licenses all its data and content (with the sole exception of non-free images used to illustrate articles on local wikis) under a license that allows anyone to use, copy, amend, or distribute them. The explicit purpose of doing so is so that anyone wishing to can not only redistribute it, but if they are unhappy with its prospects in WMF's custodianship, they can take all of it and archive it or fork from it - that is, start their own version based on all content, descriptions, data and articles they wish to take and use.
That right is enshrined on Wikipedia in policy and license - it's known as the "*right to fork*" [ie, to create derivatives and copies]. Our forking FAQ http://en.wikipedia.org/wiki/Wikipedia:FAQ/Forking expands on this giving details of where data can be downloaded, as well as Wikipedia holding a list of websites that mirror its contenthttp://en.wikipedia.org/wiki/Category:Websites_which_use_Wikipediafor anyone's use.
As the financial market crash proved, promises made by one organization are only useful insofar as that organization can promise to endure and meet them. Our approach is to spread our content and make sure others know we actively support re-archiving and reuse of it, ensuring that copies and archives will always exist.
At worst I cannot be sure if all data is routinely provided - a staff member can comment on this - but the policy, rights, traditions, choice of license, and endorsement of other sites doing so in practice, is our way of ensuring a practical commitment is made.
FT2
On Thu, Jun 2, 2011 at 12:29 PM, Fae faenwp@gmail.com wrote:
Hi,
I'm taking part in an images discussion workshop with a number of academics tomorrow and could do with a statement about the WMF's long term commitment to supporting Wikimedia Commons (and other projects) in terms of the public availability of media. Is there an official published policy I can point to that includes, say, a 10 year or 100 commitment?
If it exists, this would be a key factor for researchers choosing where to share their images with the public.
Thanks, Fae