Numerous times this season I heard "I want an iPod" not "I want a Zune". That's indicative of where the market is at. That said, I still am only seeing Macs in creative shops or hair salons.
This is just the way the market works. It's not always that the better product wins (I'm not explicitly saying the Zune is the better product here). All the people I know who say "I want an iPod" want one
not because of any sort of technical merits, but because they are trendy, and their friends have one. A lot of people seem to not even be able to tell the difference between an iPod and any other mp3 player on the market. They are all just "iPods".
While this is ultimately good for Apple's position in the DAP market, it sucks for any other worthy products that might be trying to enter the market.
I think desktops will slowly disappear. I see it already. More and more offices are providing their people with notebooks. Personally, my entire family is all mobile now as well.
It will take a while, but as the performance and ability differences continue to disappear, I believe the desktop will ultimately go the way of Eniac. As Mobile Broadband continues to increase bandwidth, it will help things too.
A lot is going to have to happen for that to become a reality. First, docking stations will have to become a lot more popular. I like laptops, but I hate laptop keyboards. So I need to be able to dock my laptop and use a real keyboard, mouse, and monitor. Sure
there are laptops with huge monitors, but they suck for mobility (Show me a 15" laptop with a 30" screen that folds or rolls up into the same size as the rest of the laptop, and I'm sold).
Laptops might become more popular with the consumer market, but anybody who wants to be able to upgrade their hardware will want to stick with desktop. Unless laptops become a whole lot more upgradable, that's going to be a hinderance.
Another issue is performance, sure there are some real powerhouse laptops out there, but they are expensive. The price vs performance numbers for laptops aren't very good.
One that see a lot is heat. I have a friend who has a 19" high-end laptop, and that thing puts out enough heat to make an Eniac out of anybody. Forget about putting it on anything other than a table top. If you leave it laying on a bed for too long, it will
overheat. Sure, it might be possible to push more heat out the side vents, but that would involve more noisy power hungry fans.