Mint is currently the only Distro that is both easy to use, looks good and offers users choices that other distros don't. On top of that, the choices that Mint offers are polished, something which only Ubuntu did well until the clusterfuck that is Unity arrived.
Taking a closer look at the distro watch stats, I see that there are a number of distros that are going to overtake Ubuntu in the near future. Even Fedora with its Gnome 3 mess and its buginess is starting to overtake Ubuntu. That is how unhappy users are with it.
The sad thing is that Mark Shuttleworth will ignore all the signs of decay until developers start not bothering to package or test for Ubuntu and business partners start not returning calls because they're back to talking with Red-Hat or maybe even the Mint people. It blows me away how stubborn the man is. The signs are so clear that Unity as it is currently implemented is a failure and he refuses to budge and thinks that tablets or mobiles will use a clunky, broken GUI paradigm when Android and Chromium OS already have the open source mobile market cornered.
Sad, truly sad.