There are 3 attacks, two of which AMD claims to be immune/virtually immune to, and one which they do admit to being applicable.
Is the JS PoC for Spectre not applicable to AMD then?
I think Spectre and the JS PoC are actually the ones applicable to any modern processors (including AMDs, ARMs and probably most other chip vendors). Looks like the mitigations for these will be directly included in the browser.
EDIT : I don't even think we know of a way to fix Spectre in the kernel...