Initially, the Fortune Hunters’ Club offered a total savings of 45% off the seven multiplayer packs (three character skin packs, four map packs) that will be released for Uncharted 3. We’ve kicked this deal up a few notches and are now offering 14 total packs, 7 new packs that we will be revealing as the year progresses! As a FHC member the savings for these 14 packs will be over 60%! Current membership and any new membership purchased will include all currently available and any upcoming DLC packs for Uncharted 3 as well as an exclusive Fortune Hunters' Club theme that will let you know when new Uncharted 3 DLC hits right from the XMB of your PS3.
That's from January.
any upcoming DLC packs for Uncharted 3
This is what they recently posted about an upcoming update and upcoming DLC:
4. Will we see more map packs/character packs, and if so, will FHC members get a discount? (Trick_2092)
More DLC is coming but it’s not map packs. The FHC program is over so there will be no discount. However, all upcoming DLC is reasonably priced and will grant some very cool things that customize your character.
I'm sure they will spin it somehow(or not give a shit) but god I can never trust another word Naughty Dog says.
edit: Per Arne's request, in March Naughty Dog clarified that the FHC would be ending.