We should support biometrics—i.e. fingerprint and eventually maybe face recognition—for certain authentication actions throughout the OS. Other OSes have a concept of weak biometrics and strong biometrics based on the success/false positive rates, which is something to consider. We should also try to think about and design this in a generic way, not strictly for one biometric method.
Dan and I have been talking about how oftentimes accessibility or universal access features should just be standard features; oftentimes people don't see themselves as "disabled" or needing "accessibility" features, but could benefit from these settings. And by shipping them as standard features, they're more likely to be well-tested.
Context menus in the system don't currently show the accelerator that is attached to them. It would make sense to show shortcuts there for them to be more discoverable. Tooltips could also show shortcuts when it makes sense.