I don't like listening other people singing Christina songs.
I can do it myself too, and yet I'm not her.

Pardon me, the following is, of course, just my personal opinion (with me knowing that I long since left the area where being really impartial was either still possible or even remotely desired) but - in addition to my browser telling me that there seems to be some malfunction with the link - no one (PERIOD!!!) will ever be able to sound 'just like Xtina', at least not to my ears, and neither in my book!
There have been other artists, predating Christina considerably, like e. g. Karen Carpenter, who were really blessed with a VOICE!!
But, as far as present times and silly me are concerned, Christna is the 'standard gauge measure' to me, therefore already by definition unapproachable and unsurpassable.
I just finished watching the 'Burlesque' trailer five or so times... finally beginning to dare to realize and/or surmise that "damn" dear old 'Love' must have really managed to catch up with me after all those years...
Even if it were the 'Platonic version' only, that emotion really can grind entire ridges to pebbles, ridges where Hate would have decided to leave his dentures at the wardrobe to begin with...
Since I seem to just have encountered a 'spectre from the past', one last advice here (which cost me years[!!] to perceive as true): "Love does not necessarily work both ways like tracers... if you persist on believing it doing so, it is most likely NOT Love that is haunting you..."
Emotions can honestly be like barbed wire being where you would least like to have it... but without them, we might be nothing better than 'walking dead'...