See the Roadmap page for the official schedule.

You'll find there the currently opened Milestones, but you can use the filter panel at the upper right corner of the page to select "closed milestones" to get an overview of the whole project's life.

A short summary of what you'll find there:

• Milestones corresponding to major releases:
  • 0.12 - the upcoming major release (May 2010)
  • 0.13 - the next major release (December 2010)
  • next-major-0.1X - pool of tickets relevant for one of the next major feature releases
• Milestones corresponding to minor releases:
  • 0.12.1 - the next maintenance release for 0.12.x
  • next-minor-0.12.x - pool of tickets relevant for one of the next minor maintenance releases
  • 0.11.7.1 - micro release for the previous stable release branch (will be the last on 0.11.x)
• Milestones which don't correspond to a Trac release:
  • triaging - ticket that have to be triaged to other milestones
  • unscheduled - tickets corresponding to valid issues or feature requests but in which the Trac developers have no interest
  • not applicable - tickets which relate to Trac, but not directly to a release
  • translations - tickets used to coordinate the ongoing translation effort
  • Some plugins are maintained here:
    • plugin - mercurial
    • plugin - spam-filter

Once the triaging milestone is emptied (i.e. all tickets from the former 1.0 and 2.0 milestone are dispatched to either next-major or unscheduled), we could use triaging as the default milestone for newly created tickets, which should be more useful than the "empty" milestone currently used for this role.

Note that the planned release dates are not bounding, they should only be taken as an estimation. We're also using the dates as a way to order the milestones.

See also SeaChange for a general discussion about what users (and developers) would like to see happening in Trac.