Well you need both content and links to get top search engine rankings.  However for highly competitive keywords or keyphrases, content is only the necessary ingredient and just not sufficient.  You will need good number of quality backlinks to win over the competition.  However for a less competitive keyphrase you can win over the competition just with your content.

Here is a long time search marketer Michael Martinez emphasises a lot on content and predicts content could play a significant role in ranking given that link spamming getting rampant with the social bookmarking sites coming into the picture. However I believe its a long way to go for content to outdo or atleast get even with the value of links.

Follow the link below to read his recent interview

http://directory.sootle.com/directory-weblog/2006/09/20/michael-martinez-the-seo-interviews-part-five/

You will sure pick up a few nuggets, especially the one where he puts marketing before search while lot of people jump into search ignoring the marketing.

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