I was in your boat... have my oar.
I'm heading off to college also this fall. I like to consider myself extremely tech savvy. All my life I worked on Windows machines and was first in line for Vista. Which, by the way, Vista has been nothing but great for me, so if you do choose a Windows machine, rest assured Vista, not XP, is the way to go. But anyways, as I was getting ready to start researching laptops (around January '08) I had this crazy idea that I might want a Mac. I say crazy because I KNOW Windows inside and out. I struggle with the daily hassles of editing start-up registries and keeping up with a networks and the occasional Registry editing. But as much as I was familiar with Windows I knew Apple computers offered an ease of use, so I researched and researched and researched. The only experience I'd had on an Apple was some programming I did two years ago on eMacs. Basically the new Intel Cores put me over the edge and I figured it was a good buy. So I bought the current MacBook Pro about a week after it came out and I couldn't be happier. Now on to your questions...
1) Learning Curve
If you can navigate a Windows machine, you can navigate a Mac. There was almost no learning curve required. It's cliche, but Macs just work, there really shouldn't be much tinkering involved on the user's end. The functionality of a Mac is so streamlined that it's made for a first time user to be able to sit down and start working with Applications. That's not to say that Macs are for entry level customers. They have a depth to them possibly greater than Windows, the difference being you don't NEED to understand the inner workings of Mac OS. Even in programs, like Microsoft Office Mac, it's nearly identical to the Windows version you're used to. And programs that come with the Mac, especially iChat and iPhoto, offer an ease of use that will make you wonder why all programs can't be that user friendly. Ultimately, a person who has never picked up a computer would be happy and able to use a Mac, along with the long time computer programers who take advantage of XCode and the like.
A lot of stuff here I already mentioned but some of the differences that take a little getting used to are aesthetic. For instance, programs on a Mac have the Close, Minimize, Maximize buttons on the left. Something that was annoying for the first couple weeks as I kept on going to top right and finding no buttons... but I transitioned and now find myself going to to the left on Windows machines. Another big difference is the drop down menus and system preferences. Another thing that might both Neat Freaks is that the application windows 'float' more on a mac, but it seems to me that you can almost 'train' certain applications to be full screen. But really, other than aesthetic differences, you'll get used to the interface in a jiffy. One more thing... the keyboard. Fair warning here... Microsoft's Backspace is Apple's Delete and MS's Control is Apple's Command. That will certainly screw you up, especially considering there is a 'control' key on the Mac's keyboard also.
Ok, it's true, Windows machines have more software support in the world. They also have gaming support. It's also true that (currently) more people use Windows machines. So the pro for a Windows machine is it's heavy support. The Pro for Mac is it's friendliness, sexiness, and hey, let's face it, it's status. Many, many, many programs though that would be used in academia are very much Mac friendly, anywhere from Adobe to Mathematica. The Con for Windows is it's bulkiness and the need to keep up with it and it's Anti-virus updates. The Con for Apple is the Pro for Windows: the lack of program support that Windows has. THIS IS NOT TO SAY THAT APPLE DOES NOT HAVE SUPPORT, it just doesn't have as much.
4) Better in College
It seems to be a growing trend that more and more students, especially in college settings, are switching to Macs. I don't know if it's because it's a trend, or people are just getting tired of having to deal with Windows, but you can go to most any college's tech distribution and you'll see Mac usage growing by incredible percentages. Now every college is different. I'm attending the University of Wisconsin-Madison, which has incredible support for Mac on campus. But I was also looking at University of Illinois- Urbana, Champagne which had little to no support for Macs. So it's a matter too of what college you're going to. Also contact the department you're going in, to see what most of the prof. use. The main reason I got my Mac is for its ease of use. You can literally trust that it will do what you want it to do, and I think that's something all college kids want there computer to be... an ally you're at peace with, not the antagonist that kept you up all night trying to find where you essay had been deleted to so you can retrieve it from back-up.
Now you didn't say what you were planning on going into, but if it's the engineering or science field, I would highly recommend that you try to convince your dad to go $200 higher for the MacBook Pro which gets you, among other things, (like a 15" screen, more RAM, and a larger HDD) a dedicated Graphics Card which will almost for certain be necessary in the science/engineering field. The student discounts Apple offer are really great, plus you'll get a free iPod, but also check at your tech store on campus because occasionally they'll offer even better deals.
As a whole, Macs are more expensive, but I KNOW that it's worth it. And you can be confident that if you absolutely 100% hate Leopard, the Mac OS, you can install Windows on your machine. I know a while back (I don't know if it's still true so be nice to me) when the current generation MBPs came out it was determined that a MBP actually ran Vista better than any other common consumer notebook you could get. It's ultimately your decision. I believe most people, if they gave Macs a chance, would see that it truly is a superior product. But I also know that Vista is a fine product too and that you'll succeed. I highly recommend taking a look at Apple's many video tutorials and seeing if you like the interface and you think it's something you would be interested it. If you live near an Apple store go to it and just spend some time messing around on their computers. Have a customer assistant show you some 'cool' features. By having stores, the hardware support is phenomenal and somewhat alien in the world of repairs where companies make customers feel guilty or at fault. I told them I had a faulty Airport Card (which I did) they ordered a new one, and had it installed within three days. Fantastic. You can read similar 'success' stories by searching any blog. I hope this long-winded answer helped and take it from someone who was right where you were... you won't regret a switch to Apple!
Crystal Lake, IL