Selected answers from the Dumb SEO Questions G+ community.
Al Remetch: Reports say it will not have a big impact on SEO.
Slawomir Zdunek: Hummingbird is said not to affect SERPs and this silence in our community seems to confirm it. Personally I haven't observed any big fluctuations in the ranking. As for search results it is really hard to say if the currect results are better than the previous ones. I believe they are better but of course you can find a large number of people who say that they still bump into weird results. ;