There are decks in Commander that do run all five colors of mana that can use him effectively, such as Scion of the Ur-Dragon. He costs one of each color of the mana pie and allows you to run all five colors of mana. If you manage to get all five land types out onto the field, Draco is a 6-cost 9/9 flyer. Plus, his downside, which says you must sacrifice Draco unless you pay 10, is negated since you have the 5 types of lands to make him stay on the field for 0.
Draco also sees play in Volrath the Fallen EDH decks. Volrath has an ability that allows you to discard a creature card from your hand to give him +X/+X until end of turn where X is the converted mana cost (CMC) of the discarded creature. Since Draco has a CMC of 16, this means Volrath the Fallen can become a 22 power creature. It's a pretty funny way to knock a player out of the game with Commander damage.
There’s also a premium foil reprint of Draco available in the From the Vault: Dragons product. While Draco is hardly one of the better Dragon cards around, he does have his uses and foil Planeshift copies run from $9-12 and the From the Vault versions (which share the same artwork) are about $7-8. He’s a semi-valuable collectible card that can find a place in five-color decks, but not much else because of that nasty drawback.