Here's an post on BTCD and SuperNET (it loads slowly sometimes):

http://bitcoindark.pw/bitcoindark-supernet/

Interesting points:

(1)  BTCD is the "reference" currency for SuperNET...
Everything trades through BTCD just like on the Ripple network everything trades through XRP...
One can view BTCD and XRP as "liquidity" currencies... though BTCD also holds all the anon tech.

(2)  Because of it's special status...
The entire BTCD blockchain is stored in RAM using highly compressed "ramchains"...
Facilitating near-instant transactions and other optimal events.

(3)  In a similar way, JLH with be used as the "reference" asset for Nxt asset-to-asset trades.

(4)  This will result is a dramatic uptick in liquidity for both BTCD and JLH (and liquidity is valuable, just look at LTC).

(5)  Because 5% of SuperNET revenues will be paid to BTCD stakers in BTCD...
Buying all that BTCD will result in constant upward pressure of BTCD.