Okay, so there are two bugs here: Meltdown and Spectre. (Awesome names, right?)
Meltdown is the intel-only exploit. It allows any running process to access the memory of anything on the computer. It will basically own your entire computer and make it impossible to do anything securely. This one will have a 17-30% performance hit to fix until new hardware that isn't vulnerable comes out. OS developers likely won't wait for you to upgrade.
Spectre is a completely different bug, which affects processors of all types (Intel, AMD, ARM). It's basically a much weaker, much harder-to-exploit version of Meltdown. Basically it only allows you to access the memory of certain other types of applications, and while it is very serious and harder to patch, there's a chance that patching this won't require new hardware and won't require any performance drop.
So basically, everyone's forgeted, but Intel is especially forgeted.
