Here is where I am collecting evidence (particularly conversations) to piece together some information about Orz. Feel free to add evidence here too!
I'm going to add a bit about how Orz enjoy TrueSpace, perhaps more than where they came from. My evidence for this is the following bit of speech.
- Who are you? You are not Orz! We are Orz! Orz are happy *people energy* from the outside.
- Inside is good. So much good that Orz will always *germinate*.
Presumably, if Orz came from "Subspace" or whatnot and is now in Truespace, Subspace is "outside" and Truespace is "inside". So, Truespace is good. So good, in fact, that the Orz will *germinate* (transport/project to Truespace? reproduce in Truespace?).
- Here is *bright* and *smooth*. There other place is *hurt* Orz too much tired for keeping together.
- Other place is **Frumple**. Orz are here now, but almost not yet.,,
- Soon Orz are really here! You are help Orz with *parties*.
- Orz are looking for you, and find you. So much joy!!
- Now *smooth* place all the time, and after now never going back to outside.
I think that pretty much seals it: Orz are never going back to outside, it is just going to stay in TrueSpace. "The other place" either means Orz's home dimension, or QuasiSpace. Orz are coming to stay in TrueSpace. See my theory below.
(When stopped talking about Androsynth after Orz's first objections)
- Ahaa! I am told other Orz *cousins* you are *connected* for *camping*.
- I am so right!
- It is happiest days to not care about Androsynth anything.
- So now we can be *together* for friendly *dessert*.
- I am so right. I will tell them again.
Clearly, each Orz individual has its own knowledge. Orz who said this told other Orz that Humans would be good (to ally with? to eat?), and this Orz's idea has been confirmed by the fact that I don't care about the Androsynth. This Orz is going to tell them that it was right about Humans being good.
(When I left without allying with Orz)
- Going. Yes. Orz is go with you same place for *party*.
- Nobody is forget.
- Next is *alliance* *party*. Always promise is good to keep.
- So much pleasure is coming, Orz and the you is change together as soon as *camping* is started.
- You are not even aware, and then everyone is so happy.
- You are not forget. Alliance is promise.
- Orz are wait.
First, Orz are in fact "Them". Orz previously "invaded" QuasiSpace but were successfully driven off by the Arilou. The Arilou realized how dangerous Orz are and have been changing Humanity's "smell" to protect the Human race from being detected from the Orz. "Smell" refers to psychic ability, which the Orz can sense from another dimension. The Arilou have been supressing Humans' psychic ability so that the Orz cannot sense us.
The Androsynth experimented with their psychic abilities and/or dimensional fatigue (they are likely connected), and thus became "smelly". Orz sensed them and changed all the Androsynth into what we see as Orz ships and individuals. While the Androsynth had enough psychic ability to attract the attention of Orz, they did not have the psychic ability to resist it. Orz itself has not moved to TrueSpace yet, but rather psychically controlled and changed the Androsynth across dimensions. Thus, the Orz ships and individuals are the *fingers* of Orz -- they are individuals being controlled by Orz. This process of controlling new individuals is what the Orz means by *germinate*.
However, having learned about TrueSpace, Orz thinks it is better than where it comes from, so Orz itself is moving to TrueSpace, a process which apparently takes many years. It is easier for Orz to survive and thrive in TrueSpace than in other spaces, especially QuasiSpace (where the Arilou can resist them with their superior psychic abilities). For one thing, there are more life forms to sequestrate, like the Androsynth and Humans. So, Orz are going to establish itself in TrueSpace, and then consume all life forms. It is the intent of the Orz to to "ally" with the Humans and then slowly change the Humans and the Humans' allies like they did the Androsynth. While the Humans are being changed, the Orz will help fight the Hierarchy, with the intent of changing the Hierarchy races once they are defeated, or while they are being fought.
Additionally, Orz is the Ultimate Evil that the Spathi are afraid of: as of yet, Orz lies beyond all sensors, in another dimension or between that dimension and this one. Orz will arrive in several years and sequestrate all life forms.
The sequel to Star Control II was going to focus on the Orz as a threat. From the TFB chatlogs:
- <_Stilgar> Fwiffo- was it your intention to make the Orz the "bad guys" in StarControl 3?
- <Fwiffo> In our rambling thoughts about SC3 we did seriously consider having the Orz assume a much larger and more ominous role, opposed to the return of the Precursors.
In Star Control III, Orz probably would have arrived in TrueSpace, and been opposed by most, if not all, of the other life forms. Of course, that didn't happen because Accolade hijacked SC3 and got rid of or suckified all the interesting races like the Orz and Supox. I haven't checked, but this is my guess for the story being planned for the TimeWarp project.
There's a bit more to my theory, but it's late so I'll have to add it later.