And here I thought that the PH3 playtest would be the monk. Oh well, at least its interesting.
Wilden are based loosely on a race in Races of the Wild called the killoren. I had to actually look this up because I had no fucking clue that they ever existing in 3E and couldnt find any hard information on them via the interwebs. In a nutshell they seem similar to the wilden, but look like green cat-ish people (though they are described as looking like half-elves, I'd say the Grinch is more accurate). Anyway, I didnt read the entire racial entry because A) I'd overlooked them entirely when I did play 3E, and B) its 3E.
Wilden are plant/fey critters that have sprung from the Feywild to help protect nature, kick ass, and hug trees (depending on which racial power you activate) against incursions from the Far Realm. As such they are very ideal for primal classes, but also apparently work well with the invoker.
Their schtick is that they get one of three racial powers per encounter, but unlike the drow you have to set it up after each extended rest. So, its flexible, but not as flexible. Your appearance changes depending on which is set, which is an interesting feature. Their bodies also "move through the seasons" as they age, starting with spring and ending with winter, so that a young wilden is rich and green, while an old one is thin and withered-looking.
All in all, I like the concept and backstory for them. Its given me a good starting point for a sequal to Songs of Erui that will involve primal spirits and aberrants from the Far Realm. My main gripe is that none of my players had access to this before we started, so cannot give it a whirl and see how it works out in practice. I guess its a good excuse to run another delve so I can swap out my dwarf shaman for a wilden one.