Yes, now tracker is in the gnome git repository. Martyn sent an email to the tracker mailing list with the details and all the commands you may need to checkout the code. You can also use the web-interface to know what is going on.
The next step will be to move our work for the new tracker (SparQL, signals,…) from the codethink git to the gnome repository. Then we can work on the merge of both branches to make 0.7.x the main development line with as few regressions as possible.
The plan is to use the 0.7.x numbers for unstable (soon and often) releases and 0.8.0 for the next stable release.