The roads I take...

There's a new Mercurial repository in town!

Reed just created http://hg.mozilla.org/comm-central/ - which is where Thunderbird and SeaMonkey, and later also calendar will live in the future.

The repository is empty for now, and will stay this way at least until shortly after Thunderbird/Shredder 3.0a2, code for which should be frozen on Tuesday. Calendar code will join even later than Thunderbird and SeaMonkey, we'll wait until after Sunbird/Lighting 0.9 for that, which will be the last release that supports 1.8 branch code. In the future, all our project will be focused on comm-central and based on Mozilla 1.9.1, we'll skip 1.9.0 completely from a release Point of view.

Until we switch, tracked by bug 437643, there are still some bugs to fix - we need some slight changes on mozilla-central, which are waiting for review, calendar code needs a few small changes so we can pull it in from CVS and build Lighting with Thunderbird (also waiting for review), and our build code changes need review, I'll reach out for that soon.
Of course, we still can need all the testing we can get on building the test repository, please report any problems to me, I'll try to fix them. I'm also already trying to get build machines up for SeaMonkey so we'll still have nightlies. And I have not yet tried all test suites, I only know we run unit tests as well as before.

All in all, a numbers of things are still to be done, but we are on track for switching to Mercurial soon!