Allow the ability to define different "Record Types" for an entity so the form can automatically be different, based on the record type that is selected. For example, an Account could have record types of Competitor, Customer, Partner, Vendor, etc. and the form would be different for each. This allows you to show only the relevant information for each record type without having to create separate entities for the different variations of these record types.

Salesforce has this capability and it is very useful.