To cantilever the granite top out from the cabinets we are using counter top support brackets from Centerline Steel.
Since the IKEA cabinets don't have backs, we added a 2x6 knee-wall to support the cantilever brackets.
TW designed a cool hidden compartment where we can store an eight foot folding table inside the island. We call it the Island Hideaway :-)
I think we now qualify as full-fledged IKEA Hackers!