Some of you have probably already noticed, but for those who didn't:
Since Tuesday, 23:59 Pacific Time we're in the so-called slushy string freeze for TB3 beta2. "Slushy" in this context means that from that date on only string changes in blocker bugs will be accepted (and marked as late-l10n) until the firm string freeze next Tuesday, Feb 17 23:59 PST.
Unfortunately we screwed up a little bit shortly before the slushy string freeze date by committing some string-only patches. Something the introduction of the "slushy" period was intended to fix.
The downside of this is that some strings were introduced which might be hard to translate because the UI is still missing for those. The upside is, that because of that we don't have any more blockers left with a potential string impact, so the risk of late-l10n changes is pretty slim.
So please start your work now, if you did not already.
I'll also start an opt-in thread shortly in the mozilla.dev.l10n newsgroup.