From Magic of Incarnum, I'd say Totemist is solid Tier 3, possibly Tier 2, due to their obscenely huge number of natural attacks, and numerous other potent Soulmeld abilities.
Incarnate is probably Tier 3-4, has some decent abilities and versatility, but it isn't overpowering.
Soulborn is Tier 5, possibly Tier 6 if you're being really mean. They have some of the versatility of Meldshapers, but their Soulmeld list isn't very good, and they're pretty much only half-meldshapers. Like Fighters, they can be excellent at their specialization, but not a huge amount of good elsewhere.