Didn't all of this happen in one of the side universes anyway? I'm pretty sure Powergirl isn't part of the main DC universe anymore, due to one of the Crisis events, and she was involved in some of the setup for this.
Power Girl is still is active in the JSA All-Stars and very much in the mainstream DCU. She's just explicitly the last survivor of an alternate reality where she was Superman's cousin as opposed to her pre-crisis origins.
@Covar, I really don't think that Jaimie is actually/will be staying dead. There are five issues left in the series (the last of which is double sized), that is a lot of story left to tell.
I agree that Ryan Choi's death was poorly written and pointless. That said...his girlfriend Giganta got some sweet ass revenge on Dwarfstar (who hired the team that killed him, for those not in the know) in the pages of Secret Six. Courtesy of Gail Simone, who wrote the good half of the All New Atom and created Dwarfstar.
On the topic of the show...yeah. I will watch it. I will watch every episode that airs. I'm not saying I will like it though. Hell, the evidence at hand seems to suggest I will hate it. I wish I could get my hands on the leaked script that is supposedly floating around the web so I could I see for myself.