Yes, as the article suggests, Apple is using it for reliability and latency for their built-in services.

But if they can do it, we can't be that far from NetFlix, Google and others being able to flip the switch for their high bandwidth products.

I am curious whether iOS exposes multipath to applications.

I imagine it'd be pretty similar to the adoption curve SPDY has seen. First Chrome implemented it to talk to Google's servers, then a few other websites, and now nginx will do it for you "for free."

An insane amount of trafic is Google, and I can see them imolementing MPTCP.

Multipath TCP doesn't magically increase the amount of bandwidth either, it just allows a single TCP-like connection to use multiple internet connections. It would allow you to use all bandwidth available on multiple connections in a single TCP connection but right now we can already use all bandwidth available over multiple separate TCP connections.

The article is very weak on substance, but I imagine the encoded possibilities of heavy computation based parallel stream. The obvious challenges are timing/synchronization and additional processing based power consumption.