Australian regulators rejected attempts by Torvalds to register Linux as a trademark.
Personally, I think Mr. Torvalds has the right to the Linux trademark. As others have pointed out, it's pretty clear Mr. Torvalds coined the term.
Unfortunately, a lot of water has gone under the Linux bridge, and now is a bit late to try to enforce a trademark claim. This shows why Microsoft is so prickly when it comes to its own trademarked name: Windows. If you don't defend it, it quickly falls out of trademarkability (which is a word, dammit, in the dictionary in my head). I hear the makers of SPAM have gone through similar gymnastics with its name, though I'm not sure where that stands.
So, the moral of this story is: if you have a product name that you want to keep distinct in the marketplace, register it EARLY. Granted, hindsight is always 20/20, and Linus Torvalds probably never dreamed his creation would grow to its current stature. Still, business sense sometimes is useful for even hobbyist projects. I'm an amateur screenwriter. That doesn't mean I don't take the time to do a poor-man's copyright (mail myself the script by Post) or register it with the Writer's Guild before sending it out to anyone.
As an aside, I was supposed to write part 2 of my post on Xanadu. Well, that's not going to happen today. On the moving front, boy, I make procrastinators look like over-achieving college students. At least my boxes don't have to cross the Atlantic this time, but I don't think moving all my belongings in Glad trash bags is befitting of a sober-minded and serious programmer.
Sober minded? Serious? Ha.