Three new types of asteroid will be introduced. These will provide a combination of minerals, with each one providing a new mineral exclusive to its type of asteroid.
These three minerals will be part of enhanced blue prints for space ships.
Using these blueprints industry-oriented capsuleers will be able to build the type of ship we are all accustomed to, but because these minerals are now part of the mineral component of building the ship [and there can only ever be one type of new mineral added to a blueprint], it will enhance shield / armor / structure resistances respectively.
I am not concerned with the names, shapes, volumes and availability. Somebody will figure out relevant quantities and sundry details.
Of course the amount of mineral required will be determined by the type of ship being constructed.
The basic ship hulls will look the same, there may be variations in colours to reflect the type of enhancement in effect.
To keep existing space frames relevant, they will be much cheaper than the newly enhanced versions because the new minerals will be harder to come by and they will not be available in industrial-sized quantities, their rarity driving up the cost of the ship significantly.
As ever the risks and costs of the new opportunity should be properly balanced by the rewards gained. New hazards may be introduced as an added hurdle to harvesting these minerals [think: Mining Mercoxit].
CCP have done a remarkable job of this crazy hard balancing exercise, I'm pretty sure they can add this new opportunity to our much-beloved galaxy zoo.