When promoting the first one Amy was asked about a sequel. She said that she believes that it's in the contract.
Owing to his commitments to Grey's Anatomy, Patrick may be trickier especially if they are starting filming next month. As far as I know Grey's will still be in the last stages of production but I'm sure that things can be rescheduled.
Listed in the preliminary cast (not confirmed) as returning
Amy Adams - Giselle
Patrick Dempsey - Robert Philip
James Marsden - Prince Edward (He has said he would do musicals all the time so would probably be up for it if asked and is available)
Idinia Menzel - Nancy Tremaine
Rachel Covey - Morgan (Patrick's screen daughter)
Susan Sarandan couldn't but there's no Tiimothy Spall.
The film does have a different director and writer which is a bit of a worry.
It's interesting that Edward and Nancy are in it considering they went back to cartoon land at the end. Do they come back or do Giselle and Philip go to them?
I liked it too. This is great news, esp with same cast 