Archeologists have confirmed the presence of an Edomite nation at the time the biblical accounts say there was an Edomite nation. A number of scholars have tended to doubt that there were any nations in that part of the world in the eleventh to tenth centuries, when David and Solomon reigned in Israel. According to that view, David and Solomon were chieftans of a small group of Hebrews, and Edom didn't exist as more than a small tribe until the Assyrian period in the eighth to seventh centuries. That whole view is threatened by this find.
There's been a real reversal in scholarship on issues like this. About 50 years ago the general attitude was to doubt anything in the Bible that didn't have specific evidence (besides the record in the text) confirming it. Over the last 20-30 years, the general trend in biblical scholarship is to focus more on the final text and less on whether the historical elements are genuine, but interestingly, while they're doing that, we keep finding more and more that confirms the general picture that the evidence available 50 years ago didn't support (but didn't disconfirm either). This is just one among many such finds that are showing with ordinary standards of historical research that the general picture of the historical shape of things presented in the Bible is accurate, and a number of historical views that were once considered fundamentalist reactionism are now fairly mainstream among biblical scholars. Since that thesis was considered irrational 50 years ago (even though there was no evidence against it), this is a major redirection in the tendency of scholarly opinion.