Mox Opal spoiled! Is it any good?

After the speculations about how good Mox Opal would be, WotC has surprised us and spoiled the Scars of Mirrodin card!

I love the design and I believe it will be abused in both Legacy and Vintage. I can totally see a rise of affinity decks in Legacy and some Vintage MUD decks using it. The image isn’t very good but reads:

Mox Opal – 0
Legenday Artifact (Mythic Rare) ORLY?

Metalcraft – T: Add one mana of any color to your mana pool. Activate this ability only if you control three or more artifacts.

The suns of Mirrodin have shone upon perfection only once.

How do you like the new Mox? Does it deserve to be restricted in Vintage? Where would you play Mox Opal in Legacy/Vintage? How much will it cost?