Once the average bitcoin user realizes how transparent the blockchain is and how easy it is to link their meta data and even personal identity to their transactions, they will understand the importance of anonymity (I think the average bitcoin user does not see this yet). They will soon realize that their wives can look up their accounts because they once posted a wallet address on their facebook profile and now she can see all the porn and gambling sites where hubby spent money.
Darkcoin can leverage this growing awareness to its advantage by continuously reminding people that darkcoin prevents this type of personal infringement.
In a world fool of people stupid enough to post all their personal information on Facebook when it's no secret that Facebook sells it to anyone at all and then wonder why for example their medical insurance costs so much ("Aunt Betty died of cancer last week, just like Uncle Tom and Little Judy!

") I think Jo Public is going to be a hard sell.
The target demographic should be businesses and organisations who have a hard need for financial and informational privacy.
That's what I'd like to see - DRK devs concentrate on providing the underlying framework, so that whoever wants to can (for a fee in DRK) have their own private comms network running on top, branded however they like.
Provide the API, let third parties run the services.