Well, announcing them before imposing them is even worse (everybody panics, chaos ensues).

The ECB let them keep their current lifeline for a few more days, but it looks like it's still not sure yet whether the banks will open. (which means they probably wont - see above).

http://www.bloomberg.com/news/articles/2015-06-28/running-ou...

edit: updated with the fact that the current emergency aid from the ECB might not be enough to keep the banks open.