UPDATE: In fact I’m now trialling Xfce once again for my primary desktop because it satisfies all the criteria I outlined below as well as GNOME does, while being much more light weight.
It’s funny, I’m really only this fickle when it comes to software!
Yes, that's CC from Code Geass, the anime series Felix and I are watching!
While I think I still prefer KDE as a desktop environment, I think Gnome is more practical for what I do right now. Aside from Amarok and Ktorrent, virtually all the applications I use on a daily basis are GTK+ based, such as Gnumeric, Abiword, The Gimp, Gnucash, gEdit, Thunar (from Xfce, another nice DE), Firefox, Thunderbird… I could go on.
It is really nice to have a consistent user interface for the first time, where my applications and the desktop work and look the same. Having used GTK+ applications on KDE and Mac OS X for many, many years, it's certainly a refreshing experience.
On the whole I also prefer the simple design methodology behind a lot of what the GNOME people are doing. Despite Linus Torvald's vocal opposition to it, I believe working hard to make interfaces simpler is an admiral goal.
I've still got KDE 3.5.9 on my Athlon XP desktop, but I guess I could say I'm a GNOME user now. For what it's worth, this is another reason why I love using free and open source software, if I don't like a particular user interface or environment, or I choose to use a another one, it is completely in my power to just slot in a different one. It's fantastic!