There is not currently an API for this. I have asked them before for cloudwatch alerts or an API. Maybe it is in the pipeline?
However you can parse the RSS feed, easily with something like google feed api:
https://developers.google.com/feed/v1/
If there are no posts assume, service is operating normally. Otherwise read the text of the "post's" title parsing on the ":" the first half is the status.
for example if your latest post is
<item>
<title type="text">Performance issues: Route 53 Elevated API Error Rate</title>
<link>http://status.aws.amazon.com</link>
<pubDate>Wed, 16 Jan 2013 19:43:43 PST</pubDate>
<guid>http://status.aws.amazon.com/#route53_1358394223</guid>
<description>We are continuing to work to resolve elevated error rates to our control API. This does not impact queries to existing DNS records.</description>
</item>
Then your status is "Performance issues" until you recieve a new post with a title starting "service operating normally"