I would give so much to know a single fucking thing about anything Rose was talking about in that last update. To call her cryptic would be like calling Godzilla tall. You may be right, but it doesn't even begin to describe just how vast the quality is.
Basically, Dave had resolved to take the suicide mission, in which he severed Derse's moon from the planet, and would pilot it (somehow) to the Green Sun, because on some level he hates himself and feels really inadequate, and he's tired of being locked into his own paradoxical predestination to managing time. Rose, for reasons not entirely clear but likely very similar feelings of wanting to atone for what she thinks was royally failing at what she should have been doing, knocked him out and took his place. They're both still alive, just Dave is dreaming and Rose is probably intersecting a lot of Dream Bubbles on her way through the Outerest of Space.
I still like Vriska, I've felt bad for her this whole photo-albupdate. I wonder what's up with John, too, while I'm at it.
What's up with John is that it's the version of John who died to his denizen and spun off an alternate timeline. A version of John who never talked to Vriska (after the once), and never found his Dad's body.