Now, we have an answer. Well, sort of.
SamMobile reports that a document has surfaced that may show the estimated release dates for Kitkat making its way to various devices. They said:
Samsung is already testing Android 4.4 on the Galaxy Note 3, and now a leaked document obtained by iTechAddict suggests that the update will be coming to the Galaxy S4 and Note 3 in January next year, while yesteryear flagships will be receiving it sometime between March and April.
Here's the doc in question: