UPDATE: Oh, wait, you mean as you scroll up, the main menu goes more narrow and sticks to the top? If so, yes, and planning that for the next new theme after Preferential (which incidentally I have a design concept already for the next theme).
To existing themes… probably not, sorry. Doing a menu system like that actually requires a lot of work and even more if one were to do it to an existing theme structure; it would require a lot of recoding. It would be like trying to turn your 6-cylinder car engine into an 8 cylinder.