What happens if the Ender Dragon egg is destroyed?

Will the Ender Dragon egg ever have a use?

It's just used as a decorative trophy but other than that really has no use. It is effected by gravity, so you can pick it up by pacing a torch two blocks under it and then breaking the middle block. The dragon egg will fall onto the torch and break and you can then pick it up.

Can the Ender Dragon egg be blown up?

So basically if you try to burn them, throw them on a cactus, blow them up or leave them to despawn, (etc.) it will not work. The only way to destroy them will be by using the creative menu, or dropping them into the fires of Mount Doom void.

Is there only 1 ender egg?

For the spawn egg used to spawn the Ender Dragon, see Spawn Egg. The dragon egg is a decorative block or a "trophy item", and is the rarest item obtainable in the game, as it generates only once (or twice in Bedrock Edition).