Without any spoilers.....
I have read both episodes of season 9 and I have the next episode/volume on order. It will be released around April 13th so if you pre-order on Amazon or some such site today, you should be able to order and recive and have read the first 2 episodes.
In the first volume there is a picture of Shannen as Prue, along with a write up about her death and how hard the sisters took it. This is pretty key because Shannen owns the rights to both her image AND to the Prue Halliwell character.
Remember how in the Charmed episode where Paige went back in time and saw Prue but allways from behind? It's cause they were not allowed to show Shannen's face.
Ever notice on TNT or any other network to carry Charmed re-runs, they have allways shown Rose McCowan in the promos and not Shannen? Again... There is a reason for this.
Consider the image of Shannen in the new book AND the fact that for the first time in years Shannen/Prue are now featured in the Charmed re-run promos on WE TV, along with Shannen's new show, and you tell me if Prue is about to re-appear...
I guess you will have to read the books to find out.
Like a couple of others here... I usually don't like these comic/book things. I could not get into the Buffy comics but this seems different somehow.
They read like a TV episode and I find them very enjoyable.