I had a chat with Monica today about Polymer trying to create custom text input elements that don't wrap the built-in input and use contentEditable instead. The built-in input is a pile of legacy complexity that a modern app shouldn't need in principle. I'll let her expand on the details, but the short version is that she needs to be able to declare which keyboard the UA should show (e.g. the number one).
This sounded very similar to me to Apple's desire for a way of declaring which formatting commands the text field supports (e.g. bold, italic, etc). I suspect we could design something pretty minimal that we could get cross-browser support to ship that meets both needs.
Does this make sense for input team's backlog of work to do?