What's interesting to me is that more than a few people on TV (common folks, not reporters or news anchors) are ending a lot of their sentences with an "ah" or "uh" -- regardless of what the actual ending of the word is. I find it annoying, but that may be the origin (modern-day) of "woah" -- they say it that way, so naturally they spell it like "Noah." It certainly indicates a lack of reading other than online, where anything goes.