This one :
http://www.youtube.com/watch?v=Nk2cU60AxcY
As you can hear, along with the chorus reproduicing the same chorus of OP1, the Reversed OP2 has some vibes of OP1 "normal play".
i think there are also some words, just like it was the case for EP1 (Reversed EP1 had "i love you", "oni-chan" and "Run away" )