The deva was, until very recently, my most disliked race from Player's Handbook 2. I never really got into the whole aasimar bit in 3rd Edition, preferring tieflings for my gimped planetouched of choice. The art for devas seemed pretty meh, and likewise their racial features didnt do much to improve their image. To sum it up, while I think the race is mechanically sound it just didnt grok for me.
Then I read this.
This article is great. I was a bit disappointed by a few of the past race ecologies (namely the genasi one), but this sells the race to me. After reading it I had quite a few new ideas relating to Adrian's deva in Songs of Erui. I already knew that they could reincarnate as rakshasas if they fucked up too much, but there's some other interesting story content mixed in as well concerning primal spirits (which works out perfectly for me since my campaign is heavy in the primal theme).
It also adds some new crunch in the form of feats and new "bad deva" monsters. The feats are only for Heroic and Paragon tiers, but they add in the deva bloodline that gives you a daily utility stance that makes it harder for enemies to hit you and also causes you to glow. There are a couple feats that grant you temporary hit points if you get hit by attacks with the fire, cold, or radiant keywords. One lets you target allies with channel divinity powers instead of yourself. My absolute favorite is the paragon one that lets you stand up and immediately fly at your speed if you get revived during combat.
This is the kind of ecology article I like to see. Its stuff I want to read and use, and I whipped up a deva cleric with Heavenly Heritage for the next available game I can hop into. Considering that I've already got two leaders and I'm running a homebrew campaign, I suspect that will fall between never and not-happening. Oh well.