I haven't seen anything here about this. The LMDE development team is working on the next release "Betsy" (due out in November) and wrote in their blog:

http://blog.linuxmint.com/?p=2671

This is a pretty significant change for LMDE users. LMDE partial-rolling releases provide a really nice balance between running the latest-and-greatest versions of software and having a stable system. I also love never having to do a fresh install. We're losing these advantages.

In a comment in http://segfault.linuxmint.com/2014/0...e-named-betsy/ talking about upgrading from one release to another, Clem writes:

So, what do y'all think about this change? I feel like I'm losing the main reasons that I chose LMDE.

LMDE is a very different beast now, even before the introduction of Betsy, than it was when Squeeze was Debian testing which is when I gave LMDE a try.

I feel Linux Mint has lost its way with LMDE by trying to be to controlling.

I wonder if this is a matter of resources? Mint is trying to maintain its regular Ubuntu-based version with the regular updates while also trying to improve LMDE, and I suppose it's just too much, especially when working from Debian Testing. I hope Mint will be able to continue with LMDE. I like not having an Ubuntu base, and I'm not too bothered by having older software. In fact, I think Mint should shift to LMDE entirely and away from the Ubuntu-based version. In any case, I'll stick with LMDE for the time being. If it seems to get too buggy or unstable -- unlikely in a move to Debian stable -- then I'll have to distro-hop again until I find something that suits my limited needs.

I'm sure it is. They mentioned in their blog that they want to focus their efforts on other things, like Cinnamon. I personally like more frequent updates, but the only other decent Linux distro that I know of with partial-rolling releases (SolydXK) is also abandoning partial-rolling releases. I'll stick with LMDE for now and see how it goes.