<p>This isn't available and I don't think it's going to be made available.</p>

<blockquote>
  <p>Searches are too performance intensive to be RSS feeds.</p>
  
  <p>If you can't express your search as a set of tags (<a href="http://blog.stackoverflow.com/2008/10/tags-and-tags-or-tags/">we support and/or
  in tags, see the
  blog</a>),
  which <em>does</em> have an RSS feed, I humbly submit you aren't trying hard
  enough. :)</p>
</blockquote>

<p><a href="http://meta.stackexchange.com/questions/5857/rss-feed-for-searches">Reference</a></p>