While a Drupal 8 branch for the Search API module has been created in the summer of 2013, development ground to a halt soon afterwards due to a lack of time (and, partly, stability in Drupal 8). The Dev Days in Szeged will be the perfect occasion to start a concerted new effort to get the upgrade process going.
So, if you are using the Search API and are interested in its development and D8 version, then please join us in discussions and, of course, coding to make the D8 version of the Search API as awesome as it can be! The primary focus will be to get the Search API to a usable state in D8 and then decide on and implement framework improvements – however, once the foundation is there we will probably also start work on the new Solr module for D8, which will also enable us to identify possible flaws or blockers for that.
Discussion about the sprint is happening in #drupal-search-api, join there if you want to help!