Freebase is not going anywhere but please help yourself to our complete data dumps: http://wiki.freebase.com/wiki/Data_dumps

Since the dataset has an open-source (CC-BY) license, I am at a loss to imagine how someone could kill it.

The data that has already been released will be legal to redistribute forever (if there are still copies floating around). But google could decide at any point to stop making new dumps, and to stop hosting the existing ones. That's what I meant by "kill it".