Yes, 5600NM is the range max payload range for the A380F (333,000lb payload)
6600NM is max payload range for A380 Pax (200,000lb)
Lets take a look at why the A330-300 and A330-200 have wiped out B777-200 and B767 in regional medium range work. Then you may understand why Boeing needs the 787 series.
The A330 to alot of operators is alot more flexible.
You can put 32 LD3 containers into a pax A330-300 and 26LD3 in a A330-200...
The B777-200 can carry 32 LD3s and 301 passengers with a 508,000lb MTOW. 294,000lb OEW
The A330-300 can carry 32 LD3s with a 507,000lb MTOW , 263,000lb OEW......
Its no wonder the why A330-300 wiped out B777-200 for regional flying....the plane is 20,000lb lighter and can almost do the same job...
The B767 wasn't very flexible in terms of freight capacity. Thats why most airlines with sizable freight operation got the A330 instead of them.
The Boeing 767-300 could only carry 15 LD3 containers. or up to 4 pallets... A330 could carry 10, b772 can carry 10..
Actually , for the 7E7 , the underfloor frieght capacity is much improved, about 20 to 24ish with the standard cargo bay gas tanks .
The 787-800 is about the size of a A330-200... Fuel capacity will most likely about 37,000 to 40,000Gal range.. that would most likely mean a large center fuel tank which might eat into cargo capacity.
The more you think about it, the more the 7E7 looks like the composite version of the A330-200...