Let's start off with this -- no it's not ready, and no we don't know when it will be. Now that we got that out of the way, XDA forums member JackpotCalvin has gotten a build of CM7 to boot on the Kindle Fire. While it is still an early build, and the image rotation is off, the developer says he knows how to do some fixes to get it more polished, and we can hope for a build we can play with in the coming weeks. This is definitely a good sign for those hoping to hack up their Kindle Fire!
Source: XDA; Thanks, Ali!