Miscellaneous laptop discussions : Mac or Pc? That is the question!

Mac or Pc? That is the question!

Hello, greetings everyone!

I am a student going off to university this fall. And yes, I am already doing my research for which lap top to buy. (I'm just that excited :P)

I would like a lap top that is light enough to travel around campus and carry from class to class everyday. Additionally, one that possess style and excellent design. As with the use of the lap top - I will be only using it for typing up reports, browsing the internet, listening to music, watching movies, and doing some simple editing on photographs. My budget is 1400-1800.
As with the the technical specifications:
- Intel Core 2 Duo (I heard this is the best)
- At least 120 GB
- At least 1 GB of RAM
- Screen Size does not matter.

So the main question is -- should I go with a Mac or a Pc with such specified needs above?

Thoughts about Mac and Pc:

Mac
- Style
- Design
- No attacks from viruses, malware, etc.
- Ease of use

PC
- Style & Design (for some of them)
- Compatibility with almost all existing program
- Cheaper

I'm considering the Macbook or some other Pc laptop, possibly Dell's XPS M1330.

With the Macbook, I've read that one can run Windows XP/Vista. How does one go about doing this? Does one have to buy a Windows Vista OS from the store to install it on the lap top? Please clarify this.

Also, one last thing. From just simple browsing I have also read that the newest Mac OS aka The Leopard will be coming out this October. IF I do get a lap top this August, I know it will still come with the Mac OS X. But can one easily upgrade to the Leopard once it comes out? Just wondering...

Any ways, your thoughts/opinions/feed back would be a great help. Thanks a lot and have a nice day!