This presentation is an overview of many different mitigations spanning ~27 years. Some are quite widely implemented. I'm less familiar with the newer stuff, but here's some I've run into.
No-exec stacks: some UNIX machines, tons of systems today.
w^x: win xp+, Linux, several RTOS, OpenBSD, lots of others
It's worth noting that the new mitigations discussed in the talk are only available in -current. They'll be in the next release though (which should be coming in the next few months).
April being the best guess currently, though end of likely, because May 1st is the usual goal. The best guess being April, because it's what the (non-finished) 7.3 page says for the month right now. Of course that's not a guarantee, but it makes it likely. Also a branch of 7.3 already exists.
