Generic Reply
People are inherintly afraid of change.
The bigger the change, the greater the fear (and dislike).
I've found that most people I know dislike XP because it looks different. Sure, not liking how it looks is a valid opinion, but to simply not use it because it looks different is one of the most pathetic excuses I hear people use. Especially considering that you can change the way it looks (as pointed out earlier) in less than three mouse clicks.
If people got over the looks factor, and actually based their dislike of any operating system on real reasons (ie, the OS didn't get along very well with some hardware, or it was unstable or even system slow downs etc), then we'd all be happier (well, at least I would, because I wouldn't have to put up with people bitching on about how ugly it looks, or how "Fisher and Price" it looked).
That said, I'm not ever (and have never) going to tell someone to use the latest (and so called greatest) because it is their right to choose what OS they want to use.
In all honesty, if Khaled can implement transperancy for Windows 2000+, its not going to be to much of a hassle to add in 32bit icons with alpha layers and so forth.
I'm one person that would very much like to see some "Fisher and Price" added to mIRC (in an optional theme), but wouldn't mind whatever way the cookie crumbled.