[CSteefel]

Originally Posted by Legate of Amon Lanc

It always seemed to me that the meaning is, in other words: "You are a superstitious simpleton, Butterbur, you know nothing about the noble history, there is nothing scary about Fornost, it is a "holy place" of the Dúnedain, because their King had once dwelt there, and only because it's been destroyed by the Witch-King and has been deserted for a long time, it has the reputation of an "old haunted house" in your eyes."

Or one could interpret this slightly differently, given when Gandalf makes his statements. Perhaps this is Gandalf's way of saying that the King who has returned aims to clean things up, pointing also to the distant past when the Dunedain did live up there:

And many folk used to dwell away north, a hundred miles or more from here, at the far end of the Greenway: on the North Downs or by Lake Evendim.

which is followed by Butterbur's claim that the area is Deadmen's Dike and that it is haunted. Gandalf follows this with:

Deadmen's Dike, you say. So it has been called for long years; but its right name, Barliman, is Fornost Erain, Norbury of the Kings. And the King will come there again one day; and then you'll have some fair folk riding through.

which could be interpreted as meaning that Gandalf expects things to change for the better, not necessarily that there is no threat at all to the north. Slightly earlier, Butterbur says

...and the Rangers have all gone away, folk tell me. I don't think we rightly understood till now what they did for us. For there's been worse than robbers about. Wolves were howling round the fences last winter. And there's dark shapes in the woods, dreadful things that it makes the blood run cold to think of.

More superstition from Butterbur?? Maybe, but one could argue that the departure of the Rangers has allowed the robbers who came up the Greenway to flourish,

hiding in the woods beyond Archet, and out in the wilds north-away.

Whether the reference to "dark shapes in the woods" is real, or just the imaginings of Butterbur, I don't know. And whether the Rangers are only going to Deadmen's Dike for the purposes of a pilgrimage, it is hard to say, but I don't see the threat to Bree and the Shire has strictly coming from one direction.