There's not really anything all that compelling about Vista if you already have a system running XP. However, I'm of the opinion that it's not really worth going out of your way to try and get XP on a new system.
Of course people really need to stop using ambiguous phrases like "easy to use" which mean absolutely nothing because what qualifies as "easy to use" for one person doesn't necessarily apply to the next. For me, in a lot of ways, Windows is NOT very easy to use because it's constantly getting in my way, making me jump through these ridiculous hoops and put up with these fisher price style interfaces. Things I can take care of in under 5 seconds with a Linux command line take me 30 seconds or more with Windows.
So I couldn't tell you if Vista is any easier to use or not, because I have no idea what that means to YOU. I know what it means to ME, but I am not you.
Is it any easier to use. Just used my 2007 PC with Vista to cannibalize for parts for other computers. When my daughter and I tried to share it, it was just impossible. It acts like "Hal" on 2001 Space Odyssey. I was the administrator for the computer, but it kept telling me I didn't have authority to add programs or printers. Such a nightmare and all that money wasted