This doesn't sound very attractive to me. I'm running Debian/stable on one
of my desktops and switched to Debian/testing just recently on another
because I wanted a newer Version of PyQT. But switching to testing was
no fun. The next time when I want a newer Version of any software
than the one installed, I will just install it in /usr/local and
remove the installed outdated package. I will do that for any
other software until only essential packages are left.
It looks like Debian doesn't know what to do with releases, they have
volatile, backports and numerous unofficial projects (like debian-
desktop.org), trying to solve the problem they have with
releases. This proposal sounds like a good solution but only if
they would also give up trying to get a real release ready and leave
that for others like Ubuntu.