I am certainly aware of Ms Gaga's existence but have only seen snippets of her performance. I have no idea whether she is talented or not but she is definitely a showman/marketer. From brief interviews that I have heard, I too get the impression that behind the glitz this ain't no dumb blonde.
I was ready to accept her as a gimmick act, but was impressed when I saw her perform on the Today Show a few months ago. And she puts on one helluva show--she made a point of saying on the HBO special that she never lip-syncs. With all of the dancing that she did, she never sounded out-of-breath or out-of-tune. Of course, I'm sure the dads who brought their pre-teen daughters to the show weren't prepared for her language or some of the routines!