Why it's updated so slowly?
The most important features work. And I'm busy with other things. If you want to help with this, do!
It doesn't work on WinXP and Blender 2.36!
Sorry, right now, I don't have Windows around. I cannot check how well this thing works or does not. I am truly sorry. May I suggest either a) bother people on some Blender forums or IRC channels (I hear Elysiun's board and IRC rules), or b) Figure out what's actually wrong with it, send me a patch, and we'll get it up?
This is a bloody nightmare to install on Windows.
I concur. Once I get my Windows partitions back up, I think I'll figure out how to make an installer for this thing.
Why another modeller? Why don't you just get GMAX?
Didn't want to learn yet another modeller. So there. Besides, Blender is the One True Modeller.
Why there's no animation support in exporter?
Because I didn't understand how the Actions in Blender work. =) This stuff will be implemented through Actions anyway (not through Scenes as previously advertised) with the action cues (footsteps etc) similar to the nwnprops in style.
Note, however, that this is different from what the importer does at the moment, because I never specced this thing in a sensible way. *sigh*
The importer is dog slow / doesn't work in Windows / just plain crashes in post-2.28 Blender
Don't know, man, it wasn't my idea to get a new, "100% comptatible" Blender Python API and release it when I went to a vacation. =) Yann's importer code is so infinitely clever that I have absolutely no idea what it does and how to fix it. Hopefully someone smart who actually needs that importer will comment on it...
To me, it looks like in 2.28, FileReader class is no longer bundled with Blender. I could be profoundly wrong, though. I know that, for some obscure reason, in Linux with all Python libs actually installed, it won't still work.
The dog-slowness is apparently a feature.
I have code to contribute, can I send it in?
Sure. Let me see it. Better yet, it'd be nice if you have any idea of any of the subject matters to ask me to add you to our development team at Blender Projects. But random contributions are always welcome.
MdlViewer and the game show the model just fine, but NWN-J3D viewer and (insertopensourcetoolhere) blow up!
Sorry, I was sleeping at the wheel. Fix is in CVS - the filedependency property should probably go before the "newmodel" line (or you can just delete the filedependency line), and the last line of the model should say "donemodel" instead of "endmodel". (As you can see, NWN .mdl syntax is highly consistent. =)
How do I get the bleeding edge CVS version?

cvs -d:pserver:anonymous@cvs.blender.org:/cvsroot/neverblender login
cvs -z3 -d:pserver:anonymous@cvs.blender.org:/cvsroot/neverblender co neverblender

Just hit enter when asked for password.