You can store next gen games on external storage but you won't be able to run them unless they are on the main 1TB ssd (or proprietary cards).You can't use regular external drives for storage? Isn't the SSD storage thingie just if you want fast ass storage?
Its kind of like Playstation Vita.
At least you will be able to run older stuff off regular external drive but still this is gonna be an expensive pain in the ass for people who buys/play a lot of games.