It is what the latest video of Matt Cutts in Google Webmaster Help Youtube channel is all about. Google, Yahoo and Bing already announced that there are not considering the meta keywords that you stuff on the <head></head> part of your web pages as part of their ranking algorithm. However, on the video Matt emphasizes that you should choose carefully the meta description to be filled on your page. It should be relevant to the content and not just to stuff spammy keywords.
Aside from that, when the search engines found that the meta description set is really relevant to the overall value of the page, they will use it as the official snippet to the result pages of the search engines. Usually if the search engines find a “foul” on your description, they extract the snippets from the body of the article or content.
With this in mind, setting an appropriate meta description for a landing page on your site is quite important. It will both attract surfers and the search engine “spiders” to crawl and rank it properly.
Here’s the said video I mentioned: