I have just answered your support ticket with the same question and I am pasting my reply below in case someone else has a similar question.
Currently it is not possible to change series properties on the client. We are considering this option, yet I cannot provide any estimate on it, because the planning for the Q3 2012 release has already been completed and the tasks have been set.
The animation that a PieChart can have is the same as any other - when it is being rendered there is a short animation effect. The Transitions property can disable it when you set it to false.
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