Is there any thought on making "Keystone Runes"?

Keystone Masteries sound like they'll make things interesting, but then you look at our Runes and you see that they're exactly what Riot got rid of in Masteries this Preseason: stat micro-optimizations. All they do is give you slight stat bonuses that enable functionality.

That's all well and good, but I imagine Riot probably wants to make runes more dynamic in the future. Maybe they'll make "Keystone Quintessences" in the future that give you some special ability in exchange for raw stats.

Is that possible, Riot? Or are Runes an exception to your "no micro-optimizations" line of thinking?