Alice in Wonderland made $1 billion worldwide, won two Oscars for art direction and costume design, and is the reason all these Snow White and Wizard of Oz movies are reappearing on the big screen.
Woolverton is popular with Disney having written Beauty and the Beast, The Lion King, and Angelina Jolie’s upcoming Maleficent movie. There’s no word yet on whether director Tim Burton will be back, or whether we’ll be seeing Mia Wasikowska return as Alice and Johnny Depp as the Mad Hatter but I imagine most of the people involved with the first film will be sought.
An Alice in Wonderland 2 isn’t needed at all, but when big budget efforts such as John Carter don’t work out for the studio milking something as successful as Alice makes financial sense. Disney is already bulging out of its eyeballs with billion dollar franchises (Pirates of the Caribbean, The Avengers, and potentially Star Wars), but Disney will be more than happy to add another.