I would love to see the following planets added to the SWG universe:
Dagobah - Possible Yoda Themepark?
Hoth - Harsh environment tougher than Endor or Yavin 4
Coruscant - This would be quite a challenge to the Devs (I think)
Mon Calamari - Although if they didn't give us the Gungan underwater world, what good would this world be?
Jabba's homeworld (Nar Halla?) - cant remember the name but adding this could also be a way for them to create a third major faction (Hutt)
Others on wish list:
Re-position movie NPCs and re-do Themeparks.
Other than that, I cant wait for the expansion