Depends on what you're doing. A lot of utlity classes don't really need instances, so static methods are used. Singleton patterns are another example of where statics are useful.
How about you tell us what it's for, and then we can give a yay or nay?
I'll do my best, not sure how to explain it.
It's for a loading system that is used to queue's "Loadable" (interface) objects to be loaded, and then processes them.
It's basically so I can easily set up progress bars and the like by running through the queue and updating the screen as I go. I didn't really see a reason to have it a Singleton.
Hope that made some sense.