There a few rumours about 5th season, some are good and some are very bad, check this out:
This ones i think it's not true(unless i hope)
-Piper and Leo's baby will be killed by a demon
-Phoebe will be depressed
-Paige will get married with a client
-Piper and Leo will move out to the next door
This ones i think can be true
-Leo is gonna buy a dog
-The writters don't know if the baby will be a boy or a girl
-2 sisters will receive a new power(don't know wich ones)
-Glen will come back in unless 3 episodes
-A men will join the cast, and won't be Glen
-Leo becomes evil for a while, but then he turns good again
That's it, hope you liked.
But remember, it's nothing for sure, they are only rumours.