There is a beta program from Kindle called Write On by Kindle. It’s a place to post works-in-progress, get feedback, ask questions, possibly build a fan base, and network with other writers. It has message boards similar to the K-Boards. I found it helpful when I was writing my pitch for Otherworlders. I posted what I had in my pitch and what my concerns where, and a few authors helped me tighten it up. I’ve also posted a couple chapters from some WIP of my own and am getting feedback as I’m creating.
I would like it to be bigger and for there to be more involvement. But it’s in Beta, so maybe it will be once it launches fully.
Since it’s in Beta, to join, you have to request it.
Anyway, it’s just another resource. Feedback is one of the most valuable things a writer can have. And to get it from other writers is even better.