Gol D. Roger is waiting for Luffy?
Gol D. Roger can't really be waiting for someone to find the One Piece, can he? Isn't he dead? Unless Roger is waiting in heaven, it doesn't really make sense.
And what happens if Luffy finds the One Piece and Roger is literally waiting there for him? Luffy's gonna be like, "Now, I'm the King of the Pirates!" and Roger is gonna be like, "No, I'm the King of the Pirates and I'm still here, dude. Gimme my hat back."
Read this theory (someone else made) about it.