Hola Teniente:
Pues verás el Blu-ray SÍ que es compatible con el DVD, no debes preocuparte por eso, la colección de DVD´s no la vas a tener que tirar, te copio una info de la página
BLU-RAY.COM
2.4 Will Blu-ray support playback of DVDs?
Yes, several leading consumer electronics companies (including Sony, Panasonic, Philips, Samsung and LG) have already demonstrated products that can read/write CDs, DVDs and Blu-ray Discs using a
BD/DVD/CD compatible optical head, so you don't have to worry about your existing DVD collection becoming obsolete. Although it's up to each manufacturer to decide if they want to make their products backwards compatible with DVD, the format is far too popular to not be supported. The Blu-ray Disc Association (BDA) expects every Blu-ray Disc device to be backward compatible with CDs and DVDs.
Un saludo.