If you look at the "pie chart" of mint users on the "community page" you will see that those using LMDE is still a relatively small amount (about 10%) the vast majority run main edition (gnome) either 32 bit or 64 bit...(about 75% in total)...
Even with the new update pack system, pointed to "latest" there is still plenty of chances for regressions, breakage, dependency problems....all despite clem's valiant efforts (not his fault...it's the "nature of the beast")....one still needs to be very technically oriented...and this will likely remain the case...
As much as people complain about ubuntu, or using ubuntu as a base...they have tons of paid employees working on each edition, and though they don't get all problems out prior to release, they do a pretty good job...probably often better then the volunteers at debian can achieve...
And being in debian testing is kind of like perpetually being in a sort of "beta" state...
I had it (LMDE) on twice...both before update packs were available and now recently, with update packs...i stll found problems were developing, threw in the towel and went back to the ubuntu based mint main edition (64 bit) where i am now extremely happy and feel i have a very stable and reliable (and much better polished) system...
I'm sincerely hoping Clem will continue doing the ubuntu based mint in the future for gnome at least...
And i am currently loving Mint 11 and look forward to seeing what Mint 12 may bring forth