Has anybody seen a blue scorpion?

All scorpions glow blue/green under ultraviolet light, as demonstrated in the picture (and explained in the description right next to the picture) on the site you linked to. They don't look blue under normal lighting.

I use a special UV flashlight to find scorpions in the desert at night. They glow bright blue when the light hits them and are very easy to spot that way.

Unless you live in Ghana I doubt you will ever see them especially if they are only being found now. It's similar to the blue spider they found a few months ago somewhere.

I wouldn't expect to see them in zoos or reptile shops for a long time haha

I have seen them a few times at pet stores, apparently some stores can supply you with the colour of your choice. Ask around and you shall find something.

nope. but i like the size of that spider!