Overall, it reads pretty interestingly.
I would have to actually run a game with one or play with one to see how well balanced they are. They start their day by picking what binds they are going to use for the day. The have a very limited number of Essentia points they can allocate at the beginning of each round as a swift action. They may keep Con-10 binds active at one time. Each of their binds takes up a item slot. This reduces their magic item availablity.
20 level classes:
Incarnate (very much caster type, can do powerful binds after a quite a few levels. Basicly build up very much like wizards do in power level. Gain bonus feats in similar vein as a psion.) Alignments: LG, CG, LE, CE
Soul bind (ok, this is the fighter type. It serves exactly the same effect psionic warrior does to psions. They are fighters with half magic.) Alignments: NG, CN, NE, LN
Totemist: (Odd druid/ranger cross breed. They gain affinity with magic beasts and can take on traits off magic beast of their alignment.) Any but tend toward neutral
There are a 4 new race in the book. Azure (very human like), Duskling (hobgoblin/ halfdrow looking), Rilken (humans repitiles with scales on neck and arms), and Skarns (Human reptiles with spikes growing from them)
Incarnum is basicly soul energy that uses the Indian concept of points of the body. Those points can have the energy attached to them. You basicly activate the feat/bind and declare a location. You get a glowing effect at that location and a manifestation of an item. So, if you bind "basilisk mask" to your third eye chakra you take up your brow slot or eye slot. The effect of basilisk mask reads like the following.
Mask while active grants darkvision 30ft + 30ft per additional essentia spent on it. This means if you allocated 4 of your points to this mask. You could have Darkvision 120ft and appear to be wearing a big mask. This will last until you spend the swift action to relocate all the poitns off your "Basilisk mask" or 24 hours passes.