I am very excited about this lineup, but there are bands that I don't know enough about to have an opinion.
First, the bands that I've been screaming about to come to ProgPower: Iron Savior, Andromeda, and Elvenking! FINALLY. These three bands were in my wishlist since before I came to my first ProgPower (VI), and there was still speculation as to who was coming to PP6.
Bands that I've heard a little bit and have a positive reaction: Riverside, Spheric Universe Experience, Serenity: all good bands from what I've heard, but I don't know much yet. Will by October next year, though!
Jon Oliva's Pain: similar situation to Circle II Circle for me: I love Savatage (as does the majority of this forum), but this is like diet-Savatage, it's an unrelated side project that doesn't quite own up to the classic awesome that was the previous entity of its "star" member(s). Jon Oliva's Pain is a replacement for what many want, which is a Savatage reunion. Even Jon said that that's not going to happen any time soon (who knows, though, eh?). I will probably enjoy seeing JOP for the same reason that many Joe-schmo's will: in hopes he'll play some Savatage songs. I don't think I'm too inaccurate there.
The rest of the lineup, I know next to nothing about their material, so I'll have to check them out on my own. But I am super excited...because I am getting three of the four bands I've been screaming for since I discovered ProgPower (the fourth being Falconer...I'm still holding on for the future!). Can't wait till the headliners manifest.