It will be interesting to see how this coin develops, whether it fills the darknet vacuum left by Darkcoins name change, or implodes as a scam. Anyone else watching this develop?
There is no vacuum you speak of. As a matter of fact, Bitcoin is still the leader in the Darknet. Dash is rebranding to distance it's perception that it's only utility was for nefarious purposes. Cash is used for nefarious purposes, but it's not called Dark Cash. Sure the anonymity Dark Send provides could in theory be used for lesser than legal purposes, but nobody can control that anyways.
The fact is the darknet really adopted Darkcoin on a mass to begin with and it's always been niche. The rebranding is breaking the paradigm that many perceived it only served a niche purpose, lesser than one like Bitcoin, which we know to be inferior in many respects except for in terms of adoption. Bitcoin reigns in the adoption of users for all uses from paying bills, buying goods, investing, speculating, and any other service (legal or not).
Dash is trying to give to public image of it being the superior choice or at least a complement to Bitcoin implying it's digital cash. Cash is quite anonymous.
For the sake of argument, let's say you want to buy something personal that you may not be comfortable having records of what you purchased. I feel it's perfectly reasonable to feel and desire anonymity for some transactions. What if you happened to have a fetish you rather keep secret from others because of personal embarrassment or simply you don't like the idea of a nanny state watching your every move.
Hell what if you live in a country that limits free speech and you desire to pay for a VPN without having it on your credit history?
No vacuum was created, but instead only new horizons set. All the features loved by those seeking anonymity are still present.