Running, like from a users point of view?
Why do they care?
It's good for developers, though. There's lots of open source software that expects x11, now to port it all you have to do is change the window size and maybe set a few flags to make it fullscreen. Maybe write a double buffer extension using pixmaps because nokia removed the one that is supposed to be in x11. If you're writing a new app, there's lots of other frameworks available on the n9 that wrap all the x11 stuff away so you never see it, so it's really not that painful. The important thing is we have some options, if Nokia didn't basically tell everyone that this phone was discontinued the minute they shipped it, developers would have invested a lot more in the device. Maemo devices are real 'hacker' devices, I don't know why, but we have unofficial apps and clients for all sorts of things that just don't happen on other platforms.