Yes, the Start Menu, Taskbar, and default Desktop have changed. (You can set them back to an "old school" fit and finish if you wantsee Chapter 7, "Clicking Less.") But the changes are more than just cosmetic; XP includes many new features that were not available on previous versions of Windows, especially in the Windows 9x product line. No matter what edition you choose, you will enjoy these improvements:
Stable code base. Reduces the number of OS crashes
Windows Messenger. Communications and collaboration tool
Help and Support Center. Includes the System Restore, which helps recover from problems, and Remote Assistance, which lets friends help fix problems
Better laptop support. Improvements in power management and ClearType support. Use both on laptops.
Faster startup. Access your working environment more quickly
Wireless support. Easy connections to wireless networks
However, several key features are available only on XP Professional. I've highlighted a few:
Dynamic Disks (Chapter 3)
Offline Files support (Chapter 6)
Group Policy (mentioned a few times throughout)
Disk quotas (Chapter 6)
Remote Desktop (Chapter 10)
Multiple processor support (not covered)
The vast majority of topics covered in this book are applicable to both the Windows Home and Professional editions. On a few occasions, though, I'll point out a feature of XP Professional that I think can be helpful to the average user who's looking for more powerful ways to leverage the OS. After all, that's what this book is all about.