linux is still great to fiddle with for multiple reasons. It is the most used operating system in the high performance computing world. And the most important system to know as administrator of those HPC, administrator of data-center, websites hosting services, administrator of universities IT, some domains/companies with Unix history, hospitals IT service.. etc you name it. Linux is handy.
Next thing, it is great as a student because in the future linux takes a lot of time and has few commercial uses, and even at home it gets tiring. get a wife and children and linux is almost forgotten the first time you see yourself opening a .conf file.
BUT if feels so good to have another engine running the whole damn thing under the hood. it feels neat. windows has very old histerical raisins and some stuff are just so bloated and slow. whereas linux has refactored 100 times to get where it is now. But let's not go down the slope of troll-land.
What Spiro said can not be more true, except Android has its SDK available on windows, linux and OSX. Seems pretty logical, Android is a linux distribution. Google has linux expertise, they are a web company...
A last word about University, if you go to a respectable curiculum with a bit of history and not some new age private school that will give you 100 certifications from Sun, Oracle, SAS, Microsoft and other ridiculous papers that are pure management bullshit, you'll learn the unix way, because computer science originates from there, and widnows has just been re-inventing the wheel in a square shape.
What I mean by that, is that knowing how a linux works (but use debian for that, not ubuntu because you'll see nothing, just cute GUIs..), you'll have a step back and get a more canonical approach to computer science which I believe is great to have when you come back to the windows world.
Not only that, but for university work, you'll have to work with ssh to log on the university servers, and the correct way is from linux. (ssh -X, zsh, csh...)
However, for pure graphics, linux is a PITA if you don't have THE graphic cards for which you COULD have "nice" drivers if you happen to have a distribution that lets you have them. (hint: get an nVidia and don't be afraid of having to have to rebuild your kernel (if you have debian) or just use ubuntu its easier... at least at first.)
There are difficulties to get correct acceleration, and the multiplicity of systems in place in the community doesn't help. (Gallium, DRM, DRI, Mesa, Xorg, Compiz and the driver hell, nouveau, renouveau, fglrx, nv, nvidia and i'm not even talking of the issues with dual screen... that makes me cry)
But its a lot of fun
also the compilation process if just so simpler than on windows.
"apt-get install build-essentials" is the only thing you need before you can code.
I don't know how many URLs you have to browse before you can download a compiler on windows, and how difficult it will be to setup all the libraries you need to link correctly with your project.
on linux its often all prepared. you have autotools and cmake , everything is tightly organized in the distribution and libraries install all in the same place, so cmake package finders never loose whereas on windows....
for example, boost library, the most useful libraries set for C++ ever, you guessed it, one apt-get install only before you can use it in your code, in windows you are usually HOURS away. you need to build it, configure the projects .. aaaargh the pain, i can still feel it. fortunately there is a guy who does a binary package for windows but it matches your compiler only if you're lucky anyway.
another thing : Emacs. of course there are Vi people who will want to argue otherwise. But really knowing Emacs (or say Vi) will give you some edge in code-text edition power over the people only knowing IDE like visual studio. (poor guys they don't even know what they loose) Downside, learning emacs is looooong, and difficult, and almost impossible alone. Also it requires knowledge of lisp to edit the unavoidable .emacs config file.
But you probably already know that
just for an ending word, many companies run some servers. these servers are greating running linux for remote administration comfort. So knowing linux.. again a plus. for middle sized companies without admins where anybody can do a bit of admin job from time to time, if you're the only one knowing how to configure iptables and to a little ./configure make make install, you'll have a serious edge in the eyes of the management. particularly when you install an apache server running some django magic with a buildbot along a gitosis service ... or whatever other stuff that are needed in companies. (mediawiki, mailservers, NFS, backups...)
If you go work at some famous big ones out there later in your life:
- google, already mentioned, they notably contribute to webkit
- intel, very active in linux development, because it is easily recompilable they can test lots of their CPU features there. c.f. powertop utility, intel c compiler...
- every single researcher out there. may it be in forest and nature (my sister in law did her thesis on a kind of forest growing model with a demonstration app using C made on unix environment), or computer scientists, biologists, doctors.. c.f vizualisation toolkits like VTK (Kitware Inc.)...
- nvidia, the fermi strategy has lead them on linux because aforementioned HPC reasons.
- IBM, Red Hat, Novell for the most famous.
excellent report that shows that: