1. "Amp correction" data. Search for my patent application and you can probably put two-and-two together.
2. Super-Hyper-Mega-Ultra-Res cabinet IRs. 32K or more samples so you capture the room along with the IR.
3. More factory cabs.
4. More user cabs.
I might have missed it but presume or hope that more preset slots (e.g. 1024) is first priority?
And/or would extra storage usage be configurable since some folks won't need or use the extras you mentioned? (Please?!)