I don't get it, our models have been accounting for latency for the last 30 years at least. We routinely use three level of caches and higly out of order memory accesses for trying to make latency manageable.

Now it is possible that our best coherency protocols simply aren't effective at high latencies, but that doesn't mean we can't come up with something workable in the future. Is there any no-go theorem in the field?