Code names include Cayman, Antilles, Blackcomb, Barts, Whistler, Onega, Turks, Seymour, Caicos, and Caspian. All are prefixed by the letters "NI" -- which apparently stands for Northern Islands (strange, since that's the code-name for the skipped 32nm shrink). Cayman cards are the most interesting of the bunch as they should replace the successful HD 5800 series with a total of 4 different chips and 11 SKUs. Apparently only two of these will be desktop products, however, with the remaining nine reserved for the professional market.
Two Antilles cards were also listed and they should be considered part of the Cayman family. Next up is Blackcomb and Bart, the latter of which should replace the Juniper core (HD 5700 series) and is listed with XT and PRO suffixes. The XT and PRO monikers usually stand for the flagship and next model down in the series (e.g. HD 5770 and HD 5750). We are not quite sure were Blackcomb fits in but there seems to be a dual-GPU variant of this card.
The list also includes three cards based on the Turks core, which should replace Redwoon HD 5600 cards, and three Caicos based cards to replace the Cedar HD 5400 core. In total, there are 7 sub-families and 10 codenames. Although very little details regarding their expected performance are available at this point, it seems AMD is getting ready to release another top-to-bottom range of cards while Nvidia is still rolling out its more affordable GeForce 400 variants.