How different it is depends on how you use XP.
My brother would keep an icon on his desktop for every application (did not use many), so Win 8 wanting him to pick everything from the screen was no big deal.
I have a couple hundred applications, accustomed to keeping desktop clean and getting apps from the Start menu. Win 7 started transitioning me to leaving more on the screen in front of me, and the dock provided by Dell and HP (concept borrowed from one of the free software desktop paradigms) helped me group some things I use less often.
Win 8, however, drives me nuts because the Start menu is hidden by default. But if I have to make the transition, I'll get used to it, probably a couple days.