A long time ago there was go.com, overture.com and so on...
Now they are gone.
Now it's Google and their page rank.
What if this goes away in a year's time?
I've always avoided doing some linking campaigns for the fear of them simply deprecating this algorithm. But now that things are getting more competitive I have no choice but to adopt this SEO strategy.
Will linking always count as a ranking factor or is this just a flash in the pan as most SEO efforts?
It's been a 10 year flash in the pan and to date nothing has entirely replaced it. It's not going away, it's only being refined.
It helps if you realize the se's don't care about links. The are looking to use citations as an indication of authority and relevance. There are other things that can be used as citations, but none of them come anywhere near the usefulness of using links as an approximation of citation.
If you can come up with a better approximation to use that measures citations, then you've got the next Google.
As wheel mentioned, it's been refined and is actually far more than just PageRank. Peter Sorivig of Google explained that PR is just one of many metrics used to rank sites. So it's not just PR and the algo has already changed many times and is still evolving, including the role that links play.
Planning today for Google to go away in a year as the dominant player is like planning in 2001 for Microsoft to become irrelevant within a year.
You reach a certain level of momentum where it takes a lot to bring you down. Even if a vastly superior algorithm came out today, it would take years for Google to lose it's top spot on the podium (like 2-3 years, not 10-20 or course). How can I be so sure?
1. The internet in general is becoming more mature and the pace of change is slowing. Most big shakeups are additive (Twitter, Facebook), rather than two companies going head to head and knocking a Google or an Amazon down.
2. My neighbor still uses MSN as his main portal because that's what came as the default on his computer. As a Google survey showed, most people don't know the difference between a search engine and a browser. This also creates inertia.
And finally, any algorithm for the foreseeable future is likely to include some version of page rank.
Now, if your question were "Will Google be here in ten years?" I would have to take my swami turban off and say "Who knows? Ten years is a long time".
That's my 2 cents anyway... and probably overpriced at that ;-)