Hmm. Quite a few of those have been done but I'm not really sure of the exact number. When the next version comes out we'll only be going up to, but not including, the Steam Age so a lot of the things on that chart won't be available until a later release. We've pretty much completed all the objects we plan on releasing in the next version and right now we're spending a lot of time improving balance and structure. But we've still got a long way to go :)
Thanks!