"Spectre" is very bad news and affects all modern CPUs
It's not yet clear whether it affects all modern CPUs, notably I have yet to see any mention of modern POWER/MIPS/SPARC-based designs. If someone has pointers, those particular cases would probably be quite interesting.
Additional exploits for other architectures are also known to exist. These include IBM System Z, POWER8 (Big Endian and Little Endian), and POWER9 (Little Endian).
I wonder to what degree some systems are affected. I believe Solaris already uses separate address spaces on SPARC for user and kernel. I haven’t looked over the SPARC architecture manual to see if they allow speculative execution beyond privilege boundaries.
