Me too. X1 sounds cool, the name suited it perfectly, X2010 is, I don't even....
I think no matter what they change it to people will always refer to it as the x1, its too late now. But I am very curious as to why the changed the name and the special event where you get it.
My guess is, they wanted to distance any associations between the X1 and real Formula 1s, because people are stupid and, they may, even if its just subconsciously, no longer regard F1 as the pinnacle of motorsports, because the X1 makes an F1 look like a Horse Carriage, and you are putting them in an environement (i.e GT5) where they directly meet head to head.
Heck I wouldn't even be surprised if people think the X1 is even a real car and think "Well I'll only watch any formula racing if they are X1s, F1s are so slow and boring) May sounds silly but GT5 is pretty mainstream and however slight the effect is, the X1 may dwindle interest in F1 cars.
Obviously any such peope wouldn't even have even half a brain but thats the world for you. And people in charge of F1 they want ratings and potrayel of F1s as high as possible.