I've been questioning WDC a lot lately too. It seems the entire future of WDC is based on Scharmbeck and a few other qualities that virtually all alt coins have now (fast transaction times, large supply, etc. Soon, I don't know if even Scharmbeck will be much of an advantage, as cryptsy should be accepting USD at any time.
Cryptsy having Alt > USD and USD > Alt trading isn't a deal-killer as far as the Scharmbeck piece of WDC is concerned. BTC has multiple BTC > USD markets available, but there's still a place for CoinBase (which I understand Scharmbeck is close to in terms of functionality) purely based on speed and convenience. Try getting USD from Mt.Gox after you sell BTC there
To the best of my knowledge, CoinBase is about the only way of getting direct BTC > USD funds into a bank account without involving various expensive third party processors and/or lengthy delays.
The piece that seems to be getting the least attention, and that should be getting far more, is the merchant tools. As a merchant myself I can tell you that the only crypto-currency that I would even consider accepting right now is BTC. Taking on the double exchange rate risk of Alt > BTC > USD is an absolute logistics nightmare. If Scharmbeck manage a smooth implementation of customer payment in WDC > known amount of USD > a daily sweep to the merchant's bank account via ACH, they will be far, far ahead of any other Alt including LTC. Yes, I know about CoinPayments.net, and it's a good service. It lacks that moment-of-sale conversion to USD and any facility for then transferring those USD to a bank account though, and that's what merchants need.
When the time comes, I hope that a great deal of emphasis will be placed on the zero chargeback / reversal risk for merchants and the absolute security for their customers. As both "friendly fraud" and stolen card databases become a more pervasive problem, it's a win/win for both parties. As a consumer, if your credit card number is stolen then it can be a massive headache. If your WDC wallet address is revealed...well...absolutely nothing happens.
That's without even getting into the reduced acceptance fees vs the standard 2-2.2% + $0.25 per transaction that merchants pay for credit card ecommerce transactions.