In a short summary, HummingBird is Google's method to provide more precise answers to user queries. Going beyond simple keyword matching Google is working to match an answer with user queries using their Knowledge Graph and methods that look at the semantics (meaning of words) of content.
Expect this will impact your site results in a few ways. One, if you tweak your site with bits of semantic HTML markup (schema.org - search engine recommendations) you will rank better (no guarantees though). This markup provides little facts that better instruct Google, Yahoo, Bing about the content in the webpages its crawling so that it can more accurately match it with user queries.
Two, its all about Google's Knowledge Graph, the more facts you can give the "brain" the better you'll rank. The graph is built up from many things, especially Google's other services; linking a Google+ Page to your website lets Google know the publisher behind the site. Adding author information (linked to a Google+ user) is another data point that links your content to the person. Each of these link facts in the Google "brain" provides more ways for it to provide answers. Moreover, the existence of the facts improve your ranking relative to the other search results since Google has more confidence in the quality of its answers.
Third, its still true that great content rules to roost. Regardless of any action above, if you've got a good website and content you're going to continue to see good results. While there are approximately 200 different things which influence Google's algorithm, helping them understand your content will give you a boast.
