What are you talking about? We've seen working POCs since last week. This isn't "largely theoretical", this is an actively exploitable hole.

Meh, it's not really very serious in the average case. It's a lot of sky-is-falling rhetoric from the infosec community. Remember Heartbleed and how it was end-of-times bad? Yeah, turned out to be a non-event. Information disclosure bugs like this are difficult to glean useful information from in widely targeted attacks.

(Obviously if you have nation states or serious criminal organizations trying to breach you regularly, this is more serious)

You clearly haven't been paying attention or reading about how this works.

Heartbleed was touted as being bad by those that didn't read too far into it. You could scrape memory, sure. But it was always random fragments. This lets you make targeted address attacks. Force a process to use that memory space through a NOOP and now you can start scraping at will. Or you can just do an entire memory dump and pull things out in plaintext (like scraping Firefox passwords, which we've seen done already).

The only reason this isn't worse is it requires the ability to execute code on the machine. It has high (near absolute) impact, but low-to-moderate on the ease of execution.