I would love to see:
1. Mustafar - I don't know about you but it'd be awesome if we had an epic chapter ending battling an incredibly powerful sith or jedi. That would fulfill my dream of living an Obi-Wan vs. Anakin confrontation!
2. Kashyyk - Wookies. Wookies. Wookies. I want a Republic wookie class too... Just saying, Bioware
3. Trandosha - I also want an Imperial Trandoshan class. Trandoshan vs. the wookies sounds cool!
4. Malachor V - Look.... there could be an epic way the Emperor somehow uses the Force to pull it back together for a secret elite Sith Academy.... Sith Warrior/Inquisitor could do so many good (or bad, whichever you prefer) things there....
5. Manaan - I really want to see how Bioware can impress me with monstrous underwater creatures
6. Unknown Planet from KoTOR 1 - That planet is beautiful. Perfect place to explore the mysterious Rakata.
7. Dxun - Epic Bounty Hunter/Trooper time.
8. Dagobah - I have a good feeling about this.... it just looks like the perfect place for a certain agent to conduct secret operations...
What I'd really like to see would be planets that the other faction couldn't go to. Not origin planets, but actual high level planets. That'd be cool to finish the Sith Warrior then roll a Jedi Knight and not have to go through Malachor V or Dagobah, you know? Just a cool idea I had.