Most preschoolers seem to love anything that involves coloring and cutting (though sometimes supervision is still needed!). My almost-4-year-old son loves doing these toilet paper roll crafts. Sometimes he is impatiently waiting for the next toilet paper roll to be finished so he can start another project. Though we have utilized other pieces of random cardboard that is laying around the house. Today we have already made Shrek and a Teenage Mutant Ninja Turtle (and he is trying to convince me to start one more...I think that will wait until quiet time tomorrow) but we probably have a stash of 15+ laying around the house!
I think most of us can relate to the experience of a young child having more fun playing with the paper and boxes at Christmas or birthday than the actual gift; the same concept may apply here, it really doesn't take much to make a child's imagination happy. Plus, it is a good activity that encourages me to sit down and interact with my preschooler as we cut, color and tape each project. But I will warn you, if your child likes making one, you probably will end up making them all the time, since there are lots of characters from which to choose!