Frankfurt has been doing that for ages (2 years now?). They just got better scanners. But they don't cover all terminals or checkpoints, so you gotta know your way around.
I don't recall it in Frankfurt last summer, but it was definitely going earlier this month. Though, they've got a weird security setup for some of the gates, so I'm sure it varied from gate to gate. Dublin and Edinburgh have had it for a while too, Dublin since last summer. Really speeds up security.
Heathrow's definitely a straggler - I'm assuming it was a more difficult project for them due to their sheer size.