I think Apple SoC are coming to the Mac sooner or later, but as I said before we would have had an hint during WWDC.
Developers can now upload apps with bitcode, so Apple can recompile them for further optimization and could allow in the future to submit apps for both ARM and Intel Mac. But a transition like this doesn't happen overnight, and would require a new operating system. Either Sierra is fully ARM compatible or ARM Mac will come in the future.
I don't really now what A10 fusion could mean, but even if I'm expecting ARM on the Mac anytime soon I don't think it is related to that.
Anyway this news is right on time, we are so excited for an Apple event and nothing is better than speculate on new trademarks