No release schedule yet, though. https://www.bit-tech.net/news/hardware/2017/03/21/amd-ryzen-fma3-fix-promise/1
I imagine they would just prevent that instruction from being executed. I can't remember where I read it but there was an article detailing what the FMA3 instruction set was and why it is unsupported. I looked around for it but can't find it again. Maybe I dreamed it. Lets hope the fix doesn't lead to a huge performance loss like what happened with the Phenom.
Gareth touched on the subject briefly in a previous post about the error. And as also pointed out in that post, the microcode will basically tell the system 'X is broken, don't do X' or 'X is broken, do Y and Z instead'. EDIT:
Yeah I did dream it! That is it though. Dude I swear it was multipage with great detail. I have to say I haven't been this excited to build a new PC since like 1999. Sadly I cannot find any reason to ditch my current rig for an AMD one at this moment. If they can maintain their performance parity, i'll gladly switch back to AMD in a few years.