From the development plans for Wikidata in 2014, it looks like a busy year.
There are a number of interesting work items but one in particular caught my attention:
Merges and redirects
bugzilla:57744 and bugzilla:38664
When two different items about the same topic are created they can be merged. Labels, descriptions, aliases, sitelinks and statements are merged if they do not conflict. The item that is left empty can then be turned into a redirect to the other. This way, Wikidata IDs can be regarded as stable identifiers by 3rd-parties.
As more data sets come online, preserving “stable identifiers” from each data set is going to be important. You can’t know in advance which data set a particular researcher may have used as a source of identifiers.
Here of course they are talking about “stable identifiers” inside of Wikidata.
In principle though, I don’t see any reason we can treat “foreign” identifiers as stable.
You?