Maybe I'm the exception, but I wasn't at all traumatized by finding out about Santa, the Tooth Fairy and the Easter Bunny too. The Easter Bunny was the last one I found out about, mainly because I could never understand how he(she/it?) would get into my room, past my alarms and traps. (I wanted to take its picture

) If anything, finding out about these stories made me want to learn more about mythology and where those stories came from and their origins, then the origins of that soceity and the people...in short, it helped kick off my love of learning more than it caused me to not trust my parents or feel I'm not loved or feel I've been lied to, etc. I'm a total myth and legend junkie now and I'm glad my parents got me interested in stories and myths like that and I fully intend to do the same with my kids...if I have any kids.
Perhaps its possible to let kids live with these stories and, when they find out, use that experience to introduce children to myths and legends from all over the world? So much of our soceity is built on characters, places and events of myths (Nike, for example, wasn't originally a sneaker and the concept of the 26 mile marathon came from the same place). If nothing else, it'll help them later on when they want to do crossword puzzles