Evan is absolutely, 100% a single point of failure. While devs like Vertoe are amazing and worth their weight in gold, I do not believe (but would love to be wrong) that they can step into Evans shoes and get Darkcoin's core code to the point it needs to be. There will come a point where Evan is no longer a single point of failure, but at this point, if Evan got hit by a bus or pulled a Mr. Spread, the value of Darkcoin would tank. I suspect that won't be the case a year from now.
As someone who had a closer look or three into the Darkcoin-coding let me slightly disagree with you.
I am 100% positive that flare, vertoe and UdjinM6, supported by "my first language is blockchain!"-Aswan, "I integrate KeePass in one weekend"-freynder and Patrick "Netfilter" McHardy can do this.
Will it be easy? Certainly not.
Will they need a helping and or two? You bet!
But Darkcoin will survive!