Ok, after scouring forum posts it looks like there is an unofficial toolset: http://forum.bioware.com/topic/529048-dai-tools/?p=17924567
"Warranty voider, author of ME3xplorer (Mass Effect 3 modding tool), Ehamloptiran who wrote BIExplorer ( Bioshock Infinite modding tool ) and others are being nice enough to make this toolset for us
SVN (link to download latest versions will be here)
http://sourceforge.n…jects/daitools/
Technical Discussion and Ehmoptiran’s mesh / texture extractor:
http://me3explorer.f…327.html#p13327
Ehalmoptiran’s forum for DAI Modding:
http://daitools.free…s.org/index.php
How to use DA_Tools.exe tool:
(See second post)
Project Timetable / Progress:
The steps are:
Identify game assets (textures, mesh, etc…)
- Read the CAS files in readable form (uncompressed) – done & released (release 10 or higher)
- Find texture and mesh examples on the CAS files – done & released (release 10 or higher)
- Extract the texture in readable form (dds) – done & released (release 10 or higher)
3a) Extract the game 3d models in readable form (obj, 3ds, fbx…) – done & released (r 10 or higher)
3b) Extract game dialog text – done & released (release 25 or higher)
3c) Extract game sound files – done by other modders, not on our tool
Modify simple Textures & Mesh
4) modify textures (gimp, Photoshop, Paint.net) – donedone & released (release 10 or higher)
4a) Modify Mesh (3ds, maya, blender, daz3D) – donedone & released (release 10 or higher)
5) Make a tool to import modded textures into game w/o crashing the game – done, not released yet
5a) Make a tool to import static mesh (statues, chairs, rocks) - done, not released yet
Modify skinned/ rigged Textures & Mesh
6) rig modded Mesh to fit the npc bodies in game (3ds, maya, blender, daz3D) – done, not released yet
7) Make a tool to import rigged mesh (armour, hair, weapons) - done, not released yet
Modify game character Textures & Mesh
8) rig modded Mesh to fit the Inquisitor bodies in game (3ds, maya, blender, daz3D) – done, not released yet
9) Make a tool to import rigged / dynamic mesh (armour, hair, weapons, body. face) - TO DO
Modify game story / flow (dialog, sound files, dialog wheel, conditionals, damage, stats, spells)
3b) Extract game dialog text – done & released (release 25 or higher)
3c) Extract game sound files – done by other modders, not on our tool
10) Identify and read conditionals, statistics, spells -
11) Make user tool to modify text, sound. statistics, spells, etc… -
12) Make tool to import the modified text, conditionals, etc into game -
** Note that 10, 11 & 12 can be done in paralel with the mesh work
*** After step 5 we can have our first mod (Change the colors of your brown Jammies! ) and some little mods like that, like “use your own flag instead of the Inquisition flag”, or “make your throne blue on Skyhold”. Perhaps we can even make Leliana a redhead if we find her hair texture.
*** After step 5a modders can add some little things like a My little pony statue to inqui’s room or a fancy door to Solas room, or whatever
**** After step 6 modders can change hair, armor and other character accessories. Finally we can try to switch the jamies for jeans ant t-shirt and get Bianca to look as rocket launcher or flame thrower
**** After step 8 we can make new mounts or new Darkspawn, or such
Doubt we get to 8 that this year but I’ve been wrong before, I thought step 5 was gonna happen in 2015 and Ehalmloptiran is doing it already 
"
SO it looks like some great progress is being made towards making mods possible. Maybe by the time I figure out how to make hair, there will be a way to actually get it into the game! I’m still not sure what “rules” or specs I need to follow to make compatible hair, though. I don’t want to get really invested and make a fancy hairstyle that the game doesn’t support.