Anyway, panic over: see this comment
http://blogs.discovermagazine.com/loom/2009/05/20/does-darwinius-exist/#comment-18433
from the Manager Editor of PLoS ONE: they have now printed fifty
identical copies of the article and made them available for purchase,
and the ICZN Executive Secretary (backed by another Commissioner)
advise that the article is now validly published, so that the name
Darwinius is now nomenclaturally valid.
Well, it seems that the editors of Plos ONE should print copies of the
papers on Aerosteon, Panphagia and Maiacetus, and apparently also of
those ugly ants, to make them valid and avoid this problem, before
someone else tries to occupy these names or rename the specimens
(although of course, this someone will suffer the consequences). The
date of publication of Aerosteon will have to change from 2008 to 2009
in such a case...