I think there never was a release announcement. But I noticed the 2.5.3-tag set on Oct.6. Now I looked into ftp.kde.org, and there really is a tarball since that date: ftp://ftp.kde.org/pub/kde/stable/calligra-2.5.3/ Also usebase.kde.org mentions 2.5.3 as latest stable release: http://userbase.kde.org/Calligra/Download Could we get this bumped?
I asked in the #Calligra channel, and got the answer "as soon as the tarball is visible, it is released".
Fixed in cvs.