I guess the Grob incident refered to is the on in South Wales earlier this year, and I guess we are all waiting to see what the AAIB report on that one has to say.
However, technology is not the whole answer. Not everyone has it, it's highly unlikely that we will reach a time where everyone has it, and it will never sort out plonkers such as the ones who gaily fly over winch-launching glider sites at circuit height and so on. Surely gliders and/or planes on the ground is a bit of a clue? In one case I know about, the offending plane was being flown by two instructors.
Don't get me wrong - technology can and does help - but it never ever will be a complete fix.