The confirmed planets so far (i'll add later on if necessary) are :
-Tython (confirmed starting point for Jedi Consular and Jedi Knight)
Tython is a planet of forests and ancient ruins
www.swtor.com/sites/all/files/en/planets/planet_land_tython_hv.jpg" border="0" alt=""/>
-Korriban (confirmed starting point for Sith Warrior and Sith Inquisitor)
Red, rocky desert planet
Original home world of the Sith
www.swtor.com/sites/all/files/en/planets/planet_land_korriban_hv.jpg" border="0" alt=""/>
-Hutta (confirmed starting point for Bounty Hunter and Imperial Agent)
Swamps and Industrial wasteland
www.swtor.com/sites/all/files/en/planets/planet_land_hutta_hv.jpg" border="0" alt=""/>
-Ord Mantell (confirmed starting point for Smuggler and Trooper)
The planet is embroiled in civil war
The planet contains mainly Saltwater seas and Islands
www.swtor.com/sites/all/files/en/planets/planet_land_ordmantell_hv.jpg" border="0" alt=""/>
-Coruscant
Capital of the Republic.
Coruscant seems to be split into levels such as Senate, Works, Gang areas
Lots to explore on Coruscant, you can see for miles and miles
Social areas on Coruscant such as the Spaceport and Galactic Senate
www.swtor.com/sites/all/files/en/planets/planet_land_coruscant_hv.jpg" border="0" alt=""/>
-Balmorra
Republic forces are supporting the local resistance on this planet.
The planet is Occupied by the Empire
www.swtor.com/sites/all/files/en/planets/planet_land_balmorra_hv.jpg" border="0" alt=""/>
-Alderaan
Alderaan is a mix of landscapes from Snow capped peaks to rolling plains to Forests
Several of Alderaan’s noble houses are battling for the throne in a brutal civil war
www.swtor.com/sites/all/files/en/planets/planet_land_alderaan_hv.jpg" border="0" alt=""/>
-Tatooine
The planet's surface consists mainly of Seas of Sand and Rock
Ex Czerka Corp mined planet. Imperial presence on planet
www.swtor.com/sites/all/files/en/planets/tatooine/planet_land_tat_hv.jpg" border="0" alt=""/>
-Dromund Kaas
Capital of the Sith Empire.
Home to the Emperor and his Dark Council, is a planet consumed with dark side energy.
www.swtor.com/sites/all/files/en/planets/dromundkaas/99dk/planet_land_dro_hv.jpg" border="0" alt=""/>
-Taris
Taris is a post-apocalyptic planet with plague infested swamps
Mention of 'vertical' enviroment aspects that maybe similar to Coruscant where you have different levels of the planet to explore
www.swtor.com/sites/all/files/en/planets/taris/886art/planet_land_taris_hv.jpg" border="0" alt=""/>
-Belsavis
Prison world maintained by the Republic
The ancient prison was constructed by the Rakatan Empire
Ice Covered with Small Pockets of Volcanic Temperate Zones
Some sort of a Dungeon called 'The Tomb' located on this planet.
www.swtor.com/sites/all/files/en/planets/belsavis/art387/planet_land_belsavis_hv.jpg" border="0" alt=""/>
-Voss
Covered in golden forests, Voss is home to both the Voss, a peaceful mystic species, and the Gormak, a species with an amazing affinity for technology.
Nightmare Lands & Forbidden Space are areas on or around Voss.
www.swtor.com/sites/all/files/en/planets/voss/an581/planet_land_voss_hv.jpg" border="0" alt=""/>
-Hoth
Frozen desolate wasteland terrain
Littered with wreckage from a major battle of what's called the Great War.
www.swtor.com/sites/all/files/en/planets/hoth/jn827/planet_land_hoth_hv.jpg" border="0" alt=""/>
Well my favorite planet would be Korriban, i always had a sense of home when i was walking its red ground in kotor, it had a deep,hidden and mysterious knowledge, challenging trials, and you could see the Sith's side of the war.