Szymon Pobiega has released PostSharp4ViewState on CodePlex. This PostSharp plug-in defines a new custom attribute [Persist]. When you apply it to an instance property of an ASP.NET page of control, it will simply... persist it in the state view!
Under the hood, PostSharp4ViewState implements the methods LoadControlState and SaveControlState.
For more information, please read the PostSharp4ViewState Code Project article. And don't forget to give him a good vote ;-).
Thank you Szymon for this great plug-in, and congratulations!
-gael