None of my ideas are concrete, nor do I have any evidence to support any of my theories, but I figured I would take a moment and place a guess or two.
First, there was the incident a while ago from someone demanding ransom of (I believe) 50 btc to stop the attack. The letter was signed with regards from "Mother Russia." Regardless of where it really came from, a quick switch to CloudFare was the response, and it seemed to work fine - as the attack seemed to be coming from (again, in my opinion) a solo amateur or group thereof.
Today, in addition to SWC, I have noticed some unusual difficulty on a couple other BTC sites. One of them is a pool I use where one can mine all sorts of alternate currencies.
Though it may be a coincidence, I tend to think it isn't. If the attack isn't 100% SWC, and is 100% btc, and is this strong, I believe that it would have to be started by a group that feels threatened by this new (and now strong) currency. Who might that be?
It was joked in the poker room that Anonymous may be behind it. This is far from the truth - as Anonymous would applaud what it is BTC followers are trying to do.
More likely, I think it is one of two broadly defined groups behind it. 1) Major Financial Institution(s) or 2) Government (or group of governments i.e. UN or EU). Since they operate hand in hand, the two groups, if one is behind it, the others are aware.
Of course, I may be WAAAYYY off, but it's my idea.
Is there a prize if I'm right? Send prizes to.... j/k :-) I hope everything gets back to normal soon.
~peps1