After only two episodes, everybody seems to be speculating about what is really going on and how it is going to end, so I’m going to put in my two cents. This is necessarily spoilerish, so it goes below the fold.
At this point there seem to be two main questions:
1) Is Yurippe really dead? This got started because she wouldn’t say how she died.
Steven den Beste speculates that Yuri has Haruhi’s power to create worlds, and has created this one as a way of dealing with her pain.
Others have noted the vital-signs monitor motif in the OP and suggested that she is actually in a coma, and all this is happening in her head. As far as I can see, that would lead to a really unsatisfactory ending.
My guess is that Yuri is really dead, and she probably died in some sort of gang violence, having drifted into delinquency after the tragic events she described. (Note her advanced knife-fighting skills.)
If we assume that Yuri and the others are really dead, and this really is some sort of quasi-Purgatory, that leads to the next question:
2) Is the rebellion justified? That seems highly questionable. Note that we haven’t heard Tenshi’s side of the story, and we haven’t seen her do anything that is really bad in the context of this world. Her actions seem no worse than what the SSS members have been doing. Also I have a strong suspicion that Yuri would have started a rebellion in any afterworld she ended up in.
If the rebellion is justified, it is hard to see how Jun Maeda is going to come up with a satisfactory ending. What are they going to do, kill God? And then what?
(In Piers Anthony’s Incarnations of Immortality series they ended up replacing God with someone more compassionate, but that ending struck me as rather insipid when I read it.)
If the rebellion isn’t justified there are some interesting possibilities. You may recall that in Haibane Renmei Show ▼
So maybe Tenshi is actually tolerating the rebellion (while making a show of trying to put it down) because rebelling is what Yuri and her friends need to do right now.