With LMDE 2 "Betsy", it appears as though the focus is shifting away from "update packs" and more towards always having the latest packages available to the user. As such, this is only a very brief look at the OS, as there isn't much functionally different between it and previous releases.
A look at the desktop. This is the MATE version, which I much prefer to the still-unfinished-feeling Cinnamon. Not much has changed, although it appears as though the welcome dialog has lost its color.
The file manager remains unchanged. I find it nice that dialog boxes are actually dialog boxes, unlike the bastardized crap many other distros and GUI developers are thrusting in our faces these days.
LMDE still uses Firefox as the default browser. Many others are available.
Instead of the regular software center, it appears as though LMDE 2 only includes the Synaptic Package Manager.
The LMDE 2 updater.
There is nothing above the hood different with this release of LMDE. It just appears as though there won't be new ISOs built every few months.