Myself, I am a SuSE guy.
I still can't peg the reason, but OpenSuSE nabbed me. I bought a laptop that had Vista pre-loaded. Took it for a test drive for a week and was simply red in the face pissed at the end of the week. Installed OpenSuSE 10.3 and everything worked (even the embedded webcam!).
I am now on 11.0. It is quirky here and there; but I am very satisfied so far.
To new Linux users, I say dual boot at first. Get your windows and your linux on. Eventually, Linux will nab you (especially when you start realizing how much crap you leave open and the box still runs along as happy as can be!)
The nice thing about Linux and X is the flexibility in UI, even running apps on remote machines with their UI routed through your local UI with nothing more than a SSH login.
You're probably right, but only because it's got a good marketing campaign, if you can call it that. Linux=Ubuntu=linux in many people's minds. I don't like Ubuntu very much, and every time I get the idea that I want to try it again, it ticks me off.
I'm a PCLinuxOS guy. I'm always smiling when I load it onto a machine, set up the wireless, and it's all humming. I LOVE not having to get up, dig through the pile of disks looking for the printer driver disk like I have to with Windows. I just add printer, and it finds the printer. People that are afraid to switch from Windows are really missing out. Linux is no longer "hard" or geeky. I don't EVER use the command line. Not ever. I have to do command line, and I'll drop that distro, Ubuntu included.
Yes, among people I know, Ubuntu is appearing on computers at a surprising pace.
I like Debian, myself.
Between Linux and Mac OS, Vista is driving a lot of migration, it seems.