As of about 12 hours ago, Feature Freeze is in effect for Vivid (15.04), leading up to the release in April.
Don't fret if you have One Last Feature to get uploaded, and don't panic and upload it untested today just to try to beat the clock. We would rather see a feature freeze exception bug and a well-tested upload than something rushed to beat a deadline. That said, the vast majority of people should be winding down new feature development now and focusing on bug fixes and polish to make 15.04 yet another great release come April. On behalf of the Ubuntu Release Team, Scott K -- ubuntu-devel-announce mailing list email@example.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-announce