At the moment the Aggregated member uses the IsConsolidated property to aggregate or not. Do I have any option if I wanted to aggregate a member but not consolidate it? With the introduction of the new member Aggregated, is there going to be a IsAggregated property created or will it always work with the IsConsolidated property?
I cannot speak for Product Development here and please don't take this as a statement of intent from the company, but I am not aware of any plan to change how Aggregated is handled.
At the end of the day, whether you want Aggregated or the regular Consolidation hierarchy, IsConsolidated just signals "numbers have to roll up". How you actually implement that in rules is up to you.