I wish I'd seen this post at Catholic Sensibility before I offered my own post below. This includes an article from an Anglican bishop that is very good in unpacking the meaning of this feast.
All I would add is to highlight the connection in the readings between the prophecy of Isaiah, and the fulfillment of Matthew: a reference to gold and frankincense (but not myrrh, hmmm!); and the reference, in Isaiah, of kings walking "by your shining radiance." Insofar as the Gospel does not refer to "kings," but Magi, I suspect the idea they are kings may have been influenced by the Isaiah passage. The historical-critical observer would say Matthew got the idea of the gifts from Isaiah; may I point out that, on sound historical-critical grounds, the Isaiah prophecy may have been offered among the exiled Jews -- i.e., in Babylon! -- so it's not unreasonable to suppose that the Magi were, in fact, influenced by Isaiah: we know a Jewish community remained in Babylon; and if that's where the magi came from, it's hardly a stretch to suppose they'd have consulted Jewish wise men on the matter... It's all speculation, anyway . . .