From the Sunday Times:

For the first time in decades there is a new title to join Mr, Mrs, Miss and Ms: the gender-neutral “Mx” as an honorific for transgender people and anyone else who does not identify with a particular gender.

Seems like a useful addition to the English language. It doesn’t have much traction in the US (yet), but the new honorific has been gaining acceptance in the UK:

Government departments, councils, high street banks, some universities, Royal Mail and driving licences all now accept Mx.

Apparently it is pronounced mux or mix. Now you can start using it!