To my knowledge none of these side-channels, even the original ones several years ago, have been exploited practically in the wild. IMHO gathering the amount of detail needed to attempt such an attack, as exemplified by the demos that have been given, would itself be prohibitively difficult. Thus the impact of yet another one remains negligible to a personal computer user, but of course the cloud providers would be super-paranoid about it.

It's worth noting that the memory protection scheme, introduced with the 286, was never intended to be a strong security barrier, but instead a means of isolating bugs and making them easier to debug.