I hope Mastercard doesn't follow Visa in making a wannabe black card for 500 dollars. If you want a black mastercard, I would go with the Saks World Elite Mastercard (no annual fee).
SAKSFIRST Saks World Elite MasterCard Features - Saks.com
It's even nicknamed the little black card, there's no annual fee, and it's a World Elite. It also helps if you shop at Saks so you can at least get some use out of the card.