Many. I am generally running Fedora, because it is related to my work. Default there is Gnome, so I need to be familiar with it. It also is a native desktop for Evo, which I also use a lot. Apart from that, Gnome tries to follow other developments in the Linux desktops closely and is not tier 2 (i.e. has its own toolkit, libs etc). KDE was always a bit of an unfamiliar thing to me, outside of the usual software I meet etc.
In short, it may sound strange to you, but I really want Gnome to succeed.