It's not really a 'new' camera. It's the exact same as the first version, just with the logic board upgraded to be slightly more power- and heat-efficient, so the processor (AF operation and IBIS operation) can be pushed a little further. It's basically just one step away from what Fuji does to their cameras with free firmware updates.
Other than that, it's the exact same system as before. They're even offering existing owners the option to send in their 'mark I' and have the logic board swapped out for a nominal fee, turning them into mark IIs.