Yep. It's now there. Missing examples, though. With those homebrew development boards you above, that hit the HaD frontpage a few days ago I've just made it a supported platform. For now antares can build the code to run on esp8266 and link all the binary blobs. You don't need to download the sdk - everything that's needed is already in antares. The port doesn't have all the goodies like ANTARES_INIT_* macros right now, earlycon or even ATOMIC_ macros, and I think I won't be adding those until proper opensource support arrives.
For now I've merged in the awesome microrl library and have a full-blown commandline with command history and editing running on esp8266 itself (Yay!) Not many fancy cmds, though. But it's something already:
blackblade > uname Antares blackblade 0.2-rc1, Insane Mushroom @ ESP8266. blackblade >
I guess I'll publish my alternative ESP8266 firmware sometime in a week or so. My goal is uboot-like environment with the ability to save environment variables to flash, send TCP and UDP packets in a simpler and more efficient and sane way, rather than crippled AT commands that come with the module by default. Stay tuned.