Read this. It's your choice if you want to believe it or not. I won't.

http://bbs3.telzone.daum.net/gaia/do/starzone/detail/read?bbsId=S000001&articleId=13473197&objCate1=6&forceTalkro=T

People say it's because he's going to the army.

Others add that he will either

1. join Changmin in signing for an extension of their SM contract, or

2. quit being a singer.

NO WAY WILL I EVER BELIEVE THIS.

But this source is from the DAUM :(((

Now inside fanwars are brewing in my Cassiopeia family, huhuhu :'(