Just in case he hadn't officially lost all his "punk" cred already, Pete Wentz has successfully sealed the deal by getting engaged to lip sync queen Ashlee Simpson. And proving they're the ultimate modern couple, Ashlee made the announcement via (of all things) the website friendsorenemies.com in a post last night: "Yes, we are thrilled to share that we are happily engaged...We consider this to be a very private matter, and we wanted to be the first to tell you." Why exactly a "very private...