And a naive question: How am I supposed to run all my Win-PC software within the Mac? I've heard that's possible.
...............
Yes it is possible - by running Windows: either from its own partition using Boot Camp - as Bob Morris and Marvin Gandall mentioned - or, my recommendation, within a virtual machine (VM):
Parallels Desktop for Mac enables you to run a full copy of Windows as a VM inside OSX.
I suggest you get the beefiest Mac you can afford (largest hard drive and the maximum amount of RAM your budget will allow). Doing so will make your Mac/Win double life go much more smoothly.
Feel free to email me off list with any questions.
And, about Boot Camp:
<http://www.apple.com/macosx/features/bootcamp.html>
.d.