In case folks hadn’t noticed, Thunderbird has decided to adopt the rapid release / schedule driven development plan that Firefox has recently started. If you want to know more, see the announcement on our tb-planning list.
As part of this, we recently moved the Miramar nightly builds from mozilla-2.0 to mozilla-aurora so that we pick up Gecko 5.0. This will let us sync up the next releases of Thunderbird and Firefox release, and will help us to sync our plans and schedules sooner.
We’re still working out all the details of getting the various channels and repositories set up, and we’ll announce once we get those running.