A number of items in your post are inaccurate, so i will kindly point them out for the discerning forum readers.
Oh, and the bit earlier about Vista and spyware is not a very good argument for the superiority of Vista.
I think it is, but there are many, many other reasons, but since you've already made your mind up, no point in going over them again.
A properly configured and managed XP system is no more vulnerable than MacOS (Linux is another story) - but it'll take more work, because there's more out there to compromise it.
This is absolutely false, and betrays just how little you know about computer security and the architecture of modern operating systems.
No matter how "secure" you get XP (and it's woefully insecure out of the box) the fact remains that its security model is completely broken. In order to do anything approaching normal use, you must run as an administrator. with this system, any application with a flaw becomes an attack vector, because compromising it gives you admin level system access. Even if it is a flaw in your pdf reader, you can do anything at that point, system wide if you compromise the code. XP is inherently insecure in this regard. This is NOT the case on either Mac OS X or Linux, which implement a proper system, much like Vista now has, of not allowing applications administrator or root access.
Saying Vista is superior because it doesn't get spyware is like saying Macs are immune to all malware. It just ain't so. The userbase was small enough that there wasn't the volume of exploits as for XP. That'll change.
Macs, Linux, and Vista all have a much more modern and secure Permissions structure, and this is why these systems will have less exploits. I will give you that since less people use the first two, they'll always have less.
I'm not hating on Microsoft - I'm pointing out that poor performance is partially their fault. Vista is a resource hog, and Microsoft is pushing DX10. This all translates into reduced support for OpenGL-based applications.
The poor performance is soley the result of poor planning and execution on the part of the graphics card vendors.
Yes, nVidia and ATI could both push out support for DirectX and OpenGL, but why go to all the effort when all the hype concerns DX10? It's a financial call too.
It has nothing to do with Direct X 10. In fact, Direct X 10 is barely supported by anything at all at the moment, only 2 cards from one vendor even support it as of this writing. What it does have to do with is that Direct X 9 and below have a majority of games, OpenGL is not used by as many games, and this gap is increasing in DirectX's favor.
Undoubtably, the bugs will get worked out of Vista,
All software of complexity such as a 50 million line operating system will always contain bugs of some sort.
