Codex Skitarii has reinforced just how bad our release was.

Interesting new models?
Interesting and different rules?
Not totally nerfed?
Actually mobile?

GW please.

Your right - Brand new army that has never before been released getting new and interesting models (its like we had never seen them before!) with new and interesting rules (like they needed to - oh - I dunno, make up a completely new set of rules). They should have been nerfed (after all we could have squatted them!) and the fact they can walk and have no transports is a shocking development in the war on being mobile...

*end sarcasm*

We needed a refresher for the DE while this is literally a whole new line. Of course they got new models and rules! They cant nerf something that's never been in the game before as well so that points moot. Mobile? Kinda. No transports but extra movement on some units - those units being light armour low T models and vehicles. Dark elder are far more mobile than skitarii.

I find my dark elder even better in this edition to be honest so I don't even understand your beef about our 'nerf'

What did they refresh?

Well they seemed to take almost everything interesting out of the DE book, so yes it is a surprise to see interesting things in a base codex. What new models did we get- frak all- one new kit which looks the same as an old one.
What did they do other than remove model options?

Although it is impossible to "nerf" new content, it is possible to make new content with bad rules- which GW have not done.

AdMech, and even eldar, have movement rules Deldar players should be lusting after. Not just extra movement, but scout across the board. Instead our movement rules are crap, our book is crap, and the release was, a huge pile of utter crap.