Warning: do not upgrade libdirectfb-1.2-0, kdelibs5 and kdelibs-bin
An update from today will make all (?) your GTK apps stop working (iceweasel with me).
This is because the following bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=569815
There was an update to that tonight, but that didn't solve the problem either (and the bug is now
Downgrading libdirectfb-1.2-0, kdelibs5 and kdelibs-bin to the testing versions will get things
"aptitude install libdirectfb-1.2-0/testing kdelibs-bin/testing kdelibs5/testing" did it for me.
After that you'd probably want to hold those packages until the bug is really fixed.