BTC-E just finished with a new software implementation, now that its done gotta think they will move on to add darkcoin.

http://www.coindesk.com/btc-e-metatrader-now-offers-multi-currency-accounts/

They know if they don't customers can easily flee for bitfinex. If they do not they are simply bad at business and deserve to watch their exchange be overtaken by bitfinex.