Why is this being blamed on the hardware (Intel/AMD/ARM) when it appears to be a problem with the way the OS is managing memory access?
Presumably (no I didn't take computer science at uni lol) it's a matter of time before people discover a similar "bug" with other things eg routers, ATMs, bank computers, power companies, traffic management, etc (that may use other CPUs)?
Hardware appliances such as routers/firewalls/switches don't usually run 3rd party apps - so even if their CPUs would be vulnerable you could not take advantage of it. ATMs/bank computers usually run a locked down OS like Windows, and traffic management systems usually do the same controlling SCADA devices.
For desktop operations antivirus solutions will be the usual line of defense against this vulnerability. And there are already AV signatures out for such code.
The real concern is for cloud and virtualized systems. Say you had some services deployed in cloud, and you had a malicious "neighbour" running on the same infrastructure - they may run this code to snoop on your system.