The news last week that even the mighty BBC News web site is starting to optimise its headlines so that its stories can be more easily found on Google and the other search engines is an indication of the immense power of search today.
I expect that pretty soon it will be a surprise to find any sites that aren’t bowing to the authority of the engines. If you’re in PR or copywriting I expect that checking your copy for the correct placement and frequency of keywords (don’t overdo it or the search engines will put you down as a spammer) will be a task akin to checking punctation and spelling. And we know that all PRs are meticulous about that!