How can combining two songs I don't even really like be so awesome?

I found an awesome new take on the "mash-up" this morning. This one is really giving Girltalk a run for his money! Jon Schmidt, a composer/arranger has combined "Love Story" by Taylor Swift and "Viva la Vida" by Coldplay to create quite an amazing piece. I probably would not call myself a fan of either of these songs...but the arrangement Schmidt puts together is quite magical. If you are into the sappy stuff, the explanation of how he came upon this mash-up is at the end of the video.