For normal users, it *SHOULD* be a non-issue, as long was you run as a limited user, and only run certified stuff. As far as I can make out, after looking at this (admittedly from a Unix angle), is it looks like you need to be a priviledged user to exploit.
But too many have egos bigger than their talent, and run with Administrator access. These people are at greater risk, but need adding to the cull list anyway
Meltdown patches for Win10 are already out, pre Win10 are still in the works. Spectre probably will likely never get fixed properly. Apple have released iOS patches for supported iPhones/iPads. Android users will have to check with their handset manaufacturers if they are vulnerable - again, non rooted Android devices are naturally more secure, rooted devices need to get their owners on the cull list.
These patches are being hyped to cause performance issues, but most of us will not notice them.
So, for most of us, usual rules apply - ensure you regularly update your PC via Windows Update. In all cases, but especially if pre Win10, be cautious of anything you are running/installing on your machine, and only run absolutely necessary browser plugins.