From what little I've seen so far:
Ocean planets:
- A strictly worse kind of Terran planet that supports less population, which of course means it's still very, very good.
- Strongly encourages social specialization to leverage the high base population as well as the increased number of social upgrades available.
- Same number of logistical slots as Terran
Ferrous planets:
- Metal galore. It's very much like a Volcanic planet, but looks like even more extreme, with more metal.
- Strongly encourages industrial specialization: It gets very few social upgrades, but lots (maximum?) industry.
- 4 less logistical slots than Volcanic/Ice.
Greenhouse planets:
- Oddball planet. It can't support a high population and doesn't appear to be very resource rich, either. The only way it seems to stand out is it gets an extra set of tactical slots, so it's easier to defend. It can be specialized into either type, getting three upgrades in both series.
Barren planets:
- Actually, this is the real oddball. Its design makes no sense whatsoever.
- Despite having no atmosphere this is actually a low-tech planet type. Unlike all the other new types it doesn't require any research to colonize.
- Supports a medium population, higher than volcanic or greenhouse but less than ice. Because living on a planet where you can't breathe is FUN!
- Gets access to lots of logistical slots for some reason (?). It has 44 (!) slots when fully upgraded.
- Same as Dwarf planet, is slightly encouraged towards social specialization with an extra upgrade slot in that development line. Of course, though, it could make an excellent trading planet with that many logistical slots.
- Overall, this planet type seems a little too good. Finding this one early in the game would give one quite a leg-up, especially if it's the crystal-heavy variant.