Another one eh? I've been happy with FF ever since the big mem fix around FF 16 or so. Surprised there is still room for another massive fix.

More info on this?

I think they are referring to this change: https://blog.mozilla.org/nnethercote/2013/10/01/memshrink-pr...

Images that aren't visible aren't decoded as they are downloaded, or something like that. It reduces peak memory usage on image-heavy pages. It should be coming in Firefox 26.

Yep that's the one. The whole web is image heavy these days so this will affect everyone. We have a lot of older computers on our network, this will really help.