I do hesitate to quote from the rulebook as it should be read from the rulebook.
The AiG Preview version is mainly for those who have the ruleset. Others may want to use just the old version of the spirit societies from the other directory.
There is currently no list. You can build a spirit from these. So a disorder (rune) spirit would have disorder spirit abilities 1 or sometimes rarely more. Darkness spirit would have similarly darkness spirit abilities one or more.
If one does not have AiG Preview at hand then Loz said something earlier about Runic Affinities for Theism. One could use those terms to deal with spirits as well - for example requiring one to have Runic Affinity to work with the spirit.
For the spirit abilities: https://notesfrompavis.wordpress.com/20 ... societies/
and take a look at the updated spirit societies.
Each rune spirit has one or more abilities from the list - usually might be only one. Create a spirit in normal fashion of RAW. For those spirit abilities that have direct equivalent in RAW - use the direct equivalent ability. So for Dark Eater spirit society you have Bless ability for a disorder spirit with sub abilities of blessing luck points, action points, totem animal skill. These exact bless enhancements are my invention - each rune spirit would probably be able to bless or curse according to the rune. Replace with others if you want. For totem animal I have named herdman and invented that it should provide Endurance as the totem animal skill. So you might get a disorder spirit with bless ability that can provide Endurance or another that can provide blessing of luck points or another that can bless Endurance skill. If the spirit ability mentions "totem animal skill" and spirit society does not mention a totem animal - there is no such skill. These spirits could act like nature spirits in RAW. For Curse spirits you could use the same abilities to curse in similar fashion (curse luck points or curse action points or curse totem animal skill).
Shapeshifter, Disease and Discorporate have direct counterparts.
For those that have no direct equivalent - invent or do not use. For example knowledge spirit might perhaps be close to ancestor spirit. Discorporate might not exist alone but come with bless ability... For Deadly you could pick Bane spirit or Death spirit - perhaps...
For the spirits - use them like you would RQ6 spirits except you need to have the runic affinity for the rune spirit. So to command darkness spirit effectively you should have darkness runic affinity.
Perhaps the most important thing is that AiG promises to give us much more flexible and rune centric way of handling the spirits - so it makes even the spirit handling a quest of Runes. There is quite a bit of very playable and enjoyable depth in the set that to me really takes advantage of the spirit of Glorantha and makes the shamans even cooler to play... The spirit section overall is one of the coolest parts of AiG from my point of view. There is quite a bit more in the spirit section of the AiG - these spirit societies are just my extrapolation from those rules - real spirit societies have not been depicted yet in the AiG.
These anyway may change with Chaosium Runequest.
In case Loz or Pete want to expand - that is up to them.