The Release date is a much sought after piece of information regarding Starbound. the beta is released.
The Starbound Team has stated that they are taking a "when it's done" approach to the release of Starbound as they do not have definitive release plans and don't want to disappoint the fans with a false release date.
While the Starbound Community have attempted to find release dates hidden in Starbound information, Chucklefish maintains that no such information is hidden and that they will outright tell the community when they have a planned release date (New posts by Mollygos indicate they don't plan on giving approximate release dates anymore).
Tiy stated in a post that Stage 1 will be the quickest and buggiest version and will sometimes be updated multiple times a day.
Starbound Beta Promo Image
The beta is planned to be released in three major stages. The first stage(known as "progenitor") was released on december 4th 2013. Approximate release dates of the other two portions are unknown. Little has been said about the full release as of yet.