I don't know what it is, but I have a pathological condition where I love hearing about the 'switcher' experience.
My brother has recently received his first MacBook, and it's interesting to see how he transitions. The concept of spotlight as an app launcher is foreign to him, as is searching. My Desktop is typically empty aside from the harddrive icon (which I never click on, but use as a quick way of seeing drive space) and any temporary files I may be working on.
My brother has a row of aliases on the Desktop (along the bottom), I guess trying to emulate the task bar (he wants to keep clutter from the dock).
I find it very interesting how subtle changes in any OS lead any user into differing ways of organising/thinking/working etc.
Just curious - what is wrong with having all the photos in the Pictures folder? Or a Microsoft User Data folder in the Documents area? My brother was kind of the same - hung up on really organising files in his own folder structure that was separate to the default folders on the Mac. It makes me think back to when I switched - I used to have folders representing different 'events' for my photos - then when I discovered iPhoto, I was ecstatic. I threw away the concept of organising files, leaving it up to the app, and concentrated on enjoying my media. Same for iTunes.