i-This and i-That
Let me toss my 2 cents. I use both OSX and XP.
There's nothing really to hate about Macs, they are nice pieces of technology. Thus there's also no need to become defensive about Macs. People who over-emphasize their likes and dislikes probably don't know much about the other side of things and are minding their own specific habits. Well I happen to know a bit of both so maybe I could share some useful word here.
Operating system:
-OSX, no question: it's safer, much more stable, and has some very nice exclusive features.
-XP is less in either of above respects, but also has a few nice exclusives, and allows certain things to be done faster.
Applications:
This depends much on how one uses his/her computer. OSX comes with a suite of programs which can be useful, some of which has no equivalent in the Windows package, for example iCal.
So it's kind of pointless to compare the i-stuff which comes with OSX with the stuff which comes with Windows since Windows users hardly use anything from Windows other than the OS itself. For most part they choose third-party software. Third-party software is the basis for both Windows usefulness and headaches: they provide more choices which is good, at the expense of often providing trouble when making these choices work (some swiftly "just work", others not.)
There are professional environments in which a Mac-based system can't be matched: movie creation and pro audio. It's not that you can't do those with a PC, it's just that a Mac can be much more powerful besides more stable and reliable given Mac-only software developments such as Final Cut, Pro Tools, and Logic, besides the unique hardware capabilities of a MacPro or even a MacBook Pro. If you're seriously into such businesses why would you discard all such power ?
Then, there is discernment: do I need all that ? Possibly not, and for your usual stuff you might possibly find a productivity edge in Windows.
Example 1: making DVDs from DV videos (not getting much into creating stuff). Well there's Procoder, DVDlab, VirtualDub and other handy tools, and even Vegas for extra possibilities, and even Adobe's Premiere with its powerful suite on both audio and graphics side. And Nero ... Really, no need for Final Cut here.
Example 2: you want to do high quality audio work really fast without opening a whole suite, and quickly apply DSP or FX or quickly get something recorded. Can't do this better than Adobe Audition, something you won't have in OSX. (Note: I mean quick tasks, not complete and beautiful as Logic). Also if you want to do MIDI sequencing and VIs and VSTs you will find a whole wealth of possibilities in Windows (Reaper, Sonar, Cubase, EWQL, Vienna, etc etc etc), though as separate parts unlike the beautiful and cost-effective completeness of Mac-only Logic.
Example 3: none of the stuff above, you just happen to be wanting to do certain things very quickly like: browsing hundreds of web pages, or thousands of JPEG images. Take the power of Opera and good ol' ACDsee to extremes and try to compare results with Mac alternatives. By the time you access one single image with QuickLook (very nice feature BTW), you could have passed through half a dozen in ACDsee. What about watching movies and listening mp3s ? Is there anything like WinAmp or KMplayer or BSplayer for Macs ? And there's ProShow ... And what about those small applications which quickly close with the ESC key, or even the choice of using this feature in several of them ? And yes, I'd be happier to resize Mac windows from anywhere in the frame, and I'd be happier to have full-screen without OSX menu showing (with some apps it's possible).
There are other examples, but: there are also plenty examples why one would be better off using OSX, the most evident one being the nice integration of Mail, Address Book and iCal, for a simple and elegant mix of efficiency, and free of visures. (The one thing I'm not totally convinced about Macs is their security against hacking.) Spaces, firewire implementaion, BootCamp are just a few exclusives that are so nice to live with.
So really, having explored the capabilities of both OSX and XP, I must say why not take advantage of both if you can ? A nice exclusive of OSX is that it allows for natively and legally running Windows in the same machine. And once it's done, it is much easier to keep a quick Windows system backup for when it goes bad: a freeware software will do it, no need for stuff like Ghost, True Image, etc. Technically, it seems that one can have OSX in a PC laptop or netbook, but not legally I suppose.
So when choosing the machine I can't see why not getting a Mac other than arguably saving money or some specific reason such as portability features (where Lenovo shines against Apple).
Hope this helps for a constructive discussion.