The way shared memory and global memory are differentiated is different from CPUs and from GCN. I'm not certain from an ISA standpoint if that concept will persist. Bonaire's level adds a flat addressing mode that at tries to handle regular and LDS data as part of a single space, although there are hazards the software must watch out for.
NVIDIA GPUs have been exposing a flat address space for generic pointers since Fermi. The same pointer can be used to point to global memory, shared memory, or thread local memory.
Optionally, you can make the pointers explicit and gain a performance advantage in certain situations.