I have used Debian since several years now and have always been either on the 'testing' or the 'sid' releases on my desktops / laptops. I never felt the need to switch to 'stable' as even sid was stable enough for me for my regular usage (with a few scripts to keep out buggy new debs).
I've seen, over time, people move to Ubuntu though. That means people really like Debian but they also wanted 'stable' releases at predictable times. If one stayed on a Debian stable release, 'bleeding edge' or 'new software' was never possible. When a new Debian release would be out, upstreams would've moved one or two major releases ahead.
So Ubuntu captured the desktop share away from Debian. The server folks wouldn't complain for lack of new features. So would this really make any difference?
Will the folks who migrated to Ubuntu go back to Debian?
(I've since moved majority of my machines to Fedora though -- but that's a different topic)