MorphOS is currently my best hope for a portable Amiga. I am so, so tempted to go buy one of the 440ep Amigas but I don't have the space right now for another desktop box (maybe when I get my house, which hopefully will be in a couple months). But I could run Amiga stuff right on one of my stack of spare Power Mac laptops.
Strangely, they're targeting the PowerBooks first, not the iBooks, which is weird since the jump is smaller from the mini to the iBook. It's not a large gulf between the iBook and the PowerBook G4, but it seems a little weird. Still, that would be worth picking up an old aluminum PB for.