First things first, let\'s make something clear:
In may 2001, when we saw the episode \'\'All hell breaks loose\'\', nothing was decided. Shannen didn\'t say she\'s going out of the show immediately... It happened a bit later, when Alyssa Milano asked the producers to be the main star, that is, that her name gets listed first in the opening credits. That\'s when Shannen gave up on Charmed.
I must admit, I was shocked at first, and to be honest, this isn\'t exactly one of my favourite episodes, but I think that seasons 5, 6, and 7 (I haven\'t seen the season 8 yet) made up for that, It is, however, unclear, how did Phoebe get out of the Underworld, or how did Leo know that Piper & Prue needed help, and then healed only Piper. But that\'s better than saying \"Shannen left us hanging, and we had to cover that up\". They did cover it up, and they did the best they could! So give them a break!
And Charmed stayed, from season 1 to season 8,
The best TV show ever!