I'm curious if asynchronous logic will get brought back in as time goes on. Multi-core is essentially desynchronising the individual cores since (iirc) clock generation and distribution is one of the most expensive parts of the processor, in both energy and size.

Historically, it lost out because of the added complexity of handshaking/synchroniser logic scattered all over the place, and the mess a mishandled metastable condition propagating through the system could cause. How that we've got transistors to burn, however, and routing is no longer done on large empty floors with crepe tape...