LMDE 7 (Linux Mint Debian Edition) is out now as the latest from the Mint team based directly on Debian instead of Ubuntu. It's their fallback plan of Ubuntu ever truly goes to shit, making sure Linux Mint could continue on and it's a target for various software they develop to also ensure their stuff works outside Ubuntu.
LMDE 7 is based on Debian 13 Trixie, which originally released back in August and comes with all the changes from that.
The Linux Mint team didn't really go into any detail on any of their own changes, their release notes gave a one-liner of "Linux Mint 7 comes with updated software and brings refinements and many new features to make your desktop experience more comfortable". Helpful. Mostly, it will be the changes from Debian 13 along with all the updates they made to the Cinnamon desktop for Linux Mint 22.2.
Source: Mint Blog