I hope that readers may know, and mayhap even sing, some fine hymns in honour of Our Blessed Lady's triumphant assumption into heaven - such as a favourite of mine, "Who is she ascends so high?"; for, after her dormition, her falling asleep in the Lord, He would not suffer her, the Immaculate Theotokos, to suffer corruption, and so resurrected and assumed her into his heaven, she, who in her virginal conception became in her very body and soul the living corporeal heaven of heavens for the Word enfleshed.
Has this struck others? It seems some illumination to me: that as her flesh and blood became heaven, for the Child conceived within her, so it was supremely fitting that that same flesh and blood should be taken into the highest heaven, as the only proper place for the Living Ark of the New and Eternal Covenant (cf. Apoc. xi, 19).
While only her bodily assumption is a defined dogma, it is clearly the common opinion, and sententia certa, that Our Lady truly died - for that is what the older term "Dormition" (κοίμησις) signifies: "falling asleep" [in the Lord], a New Testament expression for dying in Christ, that is, in the state of grace. The Dominican Rite collect Veneranda, of very old provenance, and formerly very widely used throughout the West, tells as much. Indeed, the greater number of the Liturgies of the Church testify to her death; only a few very late Latin theologians considered her as directly assumed without death intervening, and it would seem rather odd for Holy Mary not to imitate her Son in death, as she sedulously followed Him in all things.
Here, then, the collect and secret from the Dominican Rite, quite explicit in their teaching that Our Lady truly died and thereafter passed to heaven:
Veneranda nobis, Domine, hujus diei festivitas opem conferat salutem; in qua sancta Dei genitrix mortem subiit temporalem, nec tamen mortis nexibus deprimi potuit, quæ Filium tuum Dominum nostrum de se genuit incarnatum. Qui tecum vivit...
(May the venerable feast of this day confer upon us salvation, Lord; on which the holy mother of God underwent temporal death, yet could not be held in deathbonds, who had brought forth from herself Thine incarnate Son our Lord: Who with Thee liveth...)
Subveniat, Domine, plebi tuæ Dei genitricis oratio, quam etsi pro conditione carnis migrasse cognoscimus, in cælesti gloria apud te pro nobis intercedere sentiamus. Per eumdem...
(May the prayer of the Mother of God, Lord, bear up Thy people, whom though we know to have passed away on account of the condition of the flesh, we may feel her to intercede for us with Thee in heavenly glory. Through the same...)
As well as the Orthodox and the Oriental dissidents, the Church Catholic glories in praise of the Virgo Assumpta, and Traditional Lutherans and High Church Anglicans acknowledge her departure to Christ, though with reservations as to knowing if this were in the flesh or out of it (cf. II Cor. xii, 2f). Apparently the early Anglican divines held to the Assumption, the good and pious Thomas Ken (1637-1711) among them, as his hymn "Her Virgin eyes saw God incarnate born" shews.
Why bodily assumed? Because, Christ being the First-fruits of the Resurrection, after Him come all in proper order, and His Mother first among the redeemed. While before His Passion he had raised several of the dead to life, among them Lazarus, and at His Rising many of the fathers had returned to life (cf. St Matthew xxvii, 52f), these were restored for a time to earthly, mortal life; but now, having gone before us all to prepare a place for us in heaven, Our Lord commands His Mother to join Him (cf. St John xiv, 3), perfected in body and soul, to be the eschatological icon and exemplar of His Bride, the Church.
(The Orthodox very aptly also name this solemnity "the Pascha of the Theotokos" - for it is in truth her passing over, her transitus, in and through Christ the True Passover, from death to life in Him.)