TC Mag reports the codenames of some of AMD's upcoming GPUs were leaked in the changelog of the latest HWiNFO32 release:
Assuming we have the proper musical background (Britney Spears' Oops I Did It Again), we're reporting on a new update to REALiX's HWiNFO32 free system information tool which (unwillingly?) slips out the codenames of AMD's next GPUs (part of the Southern Islands).
According to HWiNFO32 v3.73's changelog, the (likely 28nm) GPUs in question are named Tahiti, New Zealand, Thames and Lombok. Unfortunately that's about it on the Southern Islands front, hopefully more leaks are incoming.