Link: What can we expect from the 2016 MacBooks
But one way or the other – hardware or software – I think 2016 is the year Apple needs to allow us to use Touch ID on our Macs. This would not only allow fingerprint login, but would also be a far more convenient way to access the secure Notes facility introduced in OS X 10.11.4, and to add Apple Pay as a payment option on the apple.com website.
Nope. I think it's much more likely to see the Apple Watch to be used for authenticating your identity on the Mac, when used with a passcode.
Put your watch on in the morning, pop in your passcode, and then let it unlock your Mac and Phone when within a ~1m radius.