I have no dobut that Longhorn will not only surpass Quartz Extreme, but Microsoft and all of the ISVs on the PC platform will make meaninful use of the capabilities in the UI. (Longhorn will be modular as well, there's much more going on than GDI++). I'm not saying one is better than the other, I'm just saying I believe that is going to happen regardless of our personal preferences. And it will affect Apple.
You would need to be able to see the future to truly have no doubts. Longhorn won't be due until the "successor" to Panther is on it's way. I find it hard to believe Microsoft will ship functionality equal to Apple.
In addition MS is pushing hardware developers to design more aesthetically pleasing hardware. So, if you remove the advantage of designe and aesthetics, what's left? Overpriced hardware.
MorganX- you still don't understand what makes Mac users tick do you. It's ALWAYS been the OS. Longhorn as I've seen it just isn't appealing as an OS. Believe me Apples design hasn't always been as good as it is today.
I just don't seem to share the enthusiasm for PCs that some people do even though I have two myself. What I see coming from Microsoft is the further commercialization of the OS. Microsoft is headed to an area in which the OS becomes a vehicle to pitch services and products. Soon their customers will be told that their computer needs to be a card carrying member of the "Trusted Computer Platform Alliance". Who's trust? We know that is in small commodity where consumers are involved.
I believe that the facts are simply PCs are cheaper computers and here in the US people LOVE cheap. However I have NO hope that Microsoft is burning the midnight oil to make their OS easier to use for consumers.
Apple will be fine. New hardware...new focus will put them deep into the black. They seem to be making the right decisions and it'll take more than a Vaio to sway those who have experience the "magic" of Macintosh to sway.