I think the future of SEO is predictive or conversation search.
It's a bit scary to think that Google can accurately predict what we are looking for by analyzing the series of queries we make. I mean, they can do a bit of that now. Even in Adwords, there's a new feature called in-buyers market where you can show your PPC ads to users who Google thinks are on the brink of buying.
As for as SEO workers, this means being able to optimize for what the user might be needing. There isn't so much we can do but using long tails in our content is a good place to start. Instead of the traditional strictly keyword-based SEO content, we can use more variations, especially long-tails, instead of exact match anchor text.
SEO will be big in the future all sites will need SEO and need to be built and prepared for SEO rules tips and tricks. It's important now that SEO is done to sites but it will be manditory in the future.
After Penguin, Panda, especially Hummingbird and the very recent Zebra, the way people used to do SEO have changed forever. We wont probably see any more PR update and Google Plus will takeover the internet. SEO is and always will be their as long as search engine remains relevant to human civilization, but the way way you do it may change from time to time. Staying updated is the key...
I don't think search is going anywhere anytime soon... SEO is probably here to stay, until a new total game-changer is about to spring on us (to do to Google what Google's search revolution did to Yahoo's "internet directory").
However, could you imagine what kind of game-changer like that could be?
I think there won't be any major changes of what makes a good SEO expert. You either have to be very intuitive (to predict various global changes that can affect their work) or be very adaptive (to quickly react to any global online marketing change). So in its essence people with those qualities would still dictate the trends and be successful.
This job sure ain't easy but it's fascinating as hell just because it always keeps you on your toes
SEO optimization isn't much changed for sites where you didn't done some heavy link building (not spam) , on sites who are in niches with weaker concuration, and where SEO is done in some relaxed manner at least my sites didn't changed their position,they are pined ...
Where you receved some fluctuation than you must concentrate on disavowing bad links and on page SEO thing need to get some boost.