Having competition is probably part of what's needed to ensure that there's some control. The problem is that none of the competition is currently approaching it from a user freedom standpoint. After all, most companies making processors are publicly traded and even if they weren't, need to sell a huge volume of them to break even and have decent per-unit costs. So trying to target what is unfortunately a very tiny niche of users isn't going to go well.
And for the truly paranoid, it's impossible to prove that the processor wasn't tampered with, that there isn't a ring below yours. You can really only ever get to the point of being able to reasonably doubt the existence of it, which won't satisfy everyone.
I think Intel is digging its own grave by taking the worst stances on issues of user freedom. Eventually, if Intel ME's power over the machine continues to increase, something bad is going to happen as a result of it, and it's going to erode the already fragile trust people have in them. The ME exploit was part 1 of that.
But what about companies like AMD, or the hundreds of ARM manufacturers that take a more passive route of not caring about user freedom? There's no imaginable consequence for that. And there's no real benefit of reversing course, either. I can't see a future where open computing will be anything more than an extreme niche with sub-par options.
One of the better scenarios I can think of is that computing as we know it today becomes a niche itself and a lot of the users do value privacy and security. This seems plausible the better that Chromebooks and phones and tablets get; the average user won't need a computer tower or a laptop with 16 GB of RAM. But I imagine it won't be good news for the prices we currently enjoy :)