I think Akon is correct, I do believe Christina is feeling some heat because of the shade she threw Gaga when she first came out and people initially started saying christina was "copying' Gaga. She made some dismissive comments " I don't know that person...is that a man or a woman" and almost 2 years later, Gaga is a cultural phenomenon ( whether some of you want to admit it or not). Not every artists has to be around 10 + years to be considered relevent or a game changer ( Janis Joplin, Jimi Hendrix, etc). I personally don't believe Gaga the artist will be around in 5 years (definetely not in the form she is in now) but I think she will be involved in music forever.

Christina was part of bubblegum teen music of the 90's and Gaga is representing the resurgence of dance music in the 2000's. Neither woman "created" anything they are part of and I feel like far too many people are taking this "rivalry" too serious. IT'S MUSIC!

Christina is singing dance music because it is popular now. Honestly though what artist is not feeling some heat from Gaga because of the MASSIVE amounts of attention she is getting and now I am sure the labels want this for their own artists, so in some ways she probably has set a new industry standard on how to promote an artist. Christina will always do well because she has a loyal fan base, but I also think Gaga is gaining a fiercely loyal following that may support her career for years to come. We'll see!