I don't think the current disgust will last too long. A lot of people will move, at some point they'll realize the grass isn't all that much greener on the other side.
There is a definite activation energy required for such a move and I'm sure that the NSA debacle provided just that for a fairly large number of parties but in the very long term the difference will be small. (In the short term it will be quite significant, at least as long as this issue is on the front-burner in the media).
The response to things like this is usually an impulse with a strong attenuation over time. It'll never quite become 0 but it will get close to 0 in a fairly short time.
The reason why right now we are seeing all this movement is because Glenn Greenwald specifically is doing an extremely good job of keeping the focus on this subject. Mainstream media would normally have completely passed an issue like this by as too technical and not enough human interest to spend a lot of time on (both of those are negatives in a news cycle that thrives on eyeballs and associated advertising).
The longer this story is kept in the public eye the bigger the fall-out will be. For now, I'm very impressed with how they are managing this, considering the adversary.
My armchair quarterback opinion, reveal the rest now and hope for a critical mass of outrage.
That's a valid concern about something which I consider the most disgusting stance a citizen could have.
As if news and outrage are supposed to be novel and entertaining. It shows that those who feel that way are not active citizens of a democracy, but passive couch potatoes, overstimulated with media BS and their own private affairs, and unable to think or act to better their country and communities.
Consider the enormity of using the same excuse for black rights ("Jim Crow laws? Seggregation? Who cares about this, didn't we already have a civil war and a KKK discussion for so many years?") or anything that took time to fix.
That is already happening, even here on HN where people consider this off-topic because it is also mainstream news.
Unfortunately, I fear the mainstream mindset towards this issue will hinge on how the major political candidates in the 2016 election choose to frame the issue. If there's widespread consensus from the leading Presidential candidates in both parties that this is not an issue - then the mainstream populous is likely to get in-line with that mindset in-support of "their" candidate.
I hope the public perception of these issues doesn't get dumbed down to political-party allegiance, but I fear it may be the case.
And those policies, which can be summarized as "we won't store our shit with US companies" will last for decades.
It may take many years before they are fully implement because nobody wants to throw money at migrating legacy with no immediate financial upside. Besides, in many cases there aren't yet sufficient competing non-US services that meet all requirements.
It will be a slow exodus, but it will also be a massive and irreversible exodus.
Unless shown otherwise I'd warrant a guess that outside the tech community the overwhelming majority or people and businesses don't care about what the NSA does.
Personally I doubt it - those backdoors have been known for years[1], and nothing happened.
[1] This report is dated 1999: http://www.heise.de/tp/artikel/5/5263/1.html
This of course does not solve the metadata problem. But I don't think the populace is really considering this angle. Protecting content is much more visceral.