To echo this on planet, too, the 1.9.1 l10n repositories are open for business.
Please read my introductory post in mozilla.dev.l10n before making changes to both the l10n-central and the releases/l10n-mozilla-1.9.1 repositories.
If you have questions, please ask in #l10n or in the newsgroup.
I have triggered builds on all comm-central apps and Firefox 3.1 to pick up the new setup, so the dashboard is all good again. The tree names remain unchanged, i.e., fx31x is the Tree towards Firefox 3.1, now picking up changes on the releases/l10n-mozilla-1.9.1 repositories as well as releases/mozilla-1.9.1 for en-US changes.