When a new Feature Request is created, it is Open for Voting. This means that it's open for the entire THWACK community to vote up.
When the product teams have decided to include the feature in an upcoming release, the status is changed to What We're Working On. More information about product roadmaps can be found here.
After a feature request has been rolled into a product, the status is changed to Implemented. This means that as of a specific release, that feature is in the product.
The final status is Closed. A feature request can be closed for any number of reasons: it's a duplicate of another request, the feature already exists in the product, or the request has gone stagnant.