Adding in that the link above has some info as well as links to spoilers (They have the first one up already at:
TheCharmedOnes.Com
If you missed and yep or so on try here
Scripts all seasons.
There is some sad news that might already be in the thread, Dorian Gregory according to sources will not be returning as "Darryl Morris" and Brian Krause's part has been cut down to about 10 eps.
Kaley Cuoco will be a regular member "Billie" a witch, and Jason Lewis will be appearing for 6 eps (which orginially Mark McGrath was suppost appear but due to schedule problems Jason took his place).
Young and the restless fans will recognize "Michelle Stafford" who will also make an appearance in at least one ep.
The reason given for Dorian and Brian's circumstances are due to budget cuts.
There is new production crew, new shooting schedule, so that the girls hours aren't as long, and hetic.
From what i understand that Brad Kern mentioned once that if there was a spin off it would be based on the character of "Billie".
Also unless i missed it and i could have, there are some promotional season 8 pictures here,
Heavenly-Charmed Gallery.