I'd like to enable an Admin to create a "default" Personalization state that will be loaded for a User the first time he accesses the application.  After that he'd (User) obviously be able to configure his own pages.  I see where there is a "DefaultProfile" and have run across the class SharedPersonalizationStateInfo , but there is not much documentation on how to use these.

Thanks! 

"DefaultProfile" is related to the Profile feature whereas SharedPersonalizationStateInfo class is related to the Personalization (WebParts) feature. SharedPersonalizationStateInfo is used for querying/removing personalization info in the database for admin purposes.

If you are trying to use WebParts Personalization, one way you can customize the "default" Personalization state is by logging in to the Shared PersonalizationScope and save personalization data. Any personalization state for authenticated users saved in shared personalization scope will be applied as default state for all users. You can toggle to shared scope if you have the enterSharedScope capability. To determine whether you're in shared scope, you can call the yourWebPartManager.Personalization.Scope property getter and check if it is PersonalizationScope.Shared.