Beginning in October 2011, Google began hiding the keywords from Organic searches, simply sending the value ‘(not provided)’. Today, Google and Yahoo do not send any keyword data from organic (non-paid advertising) searches, so you won't be able to see the keywords from those unless the user clicked on one of your paid ads.
You will, however, be able to categorize these leads so at least know where they are coming from as a general category (Campaign / Organic / Referral / Direct), as well as knowing the search engine (Google , Yahoo or Bing).
Here is how the data will typicall look:
Lead Source Type: Organic
UTM Campaign: (organic)
UTM Medium: organic
UTM Source: Google
UTM Term: (not provided)
Keyword: (not provided)
Search Engine: Google
More info here on our blog: The Opportunity of ‘(Not Provided)’ Google Keywords