The only thing I've read about it suggested that WWE might be going with Big E. Langston as the secret admirer. As of right now, that doesn't sound all that interesting.
I don't know what happened with the whole thing with Cody Rhodes. It may be that WWE simply let it die down as there wasn't a ton of interest in it from either fans or the top brass.
The idea of it being Damien Sandow is interesting, though I don't think it'd work if they turned Sandow face. His current character simply doesn't work as a babyface and I don't think Kaitlyn, at this point in her career, can really pull off a heel character.
I also think it might turn out to be something in which it's just AJ screwing with Kaitlyn as a means of distracting her. After all, they're showing Kaitlyn backstage in which she's obviously focusing on who her admirer is. The implication could be that she's so focused on who this person is that she's distracted from her upcoming title match, whenever it might be, against AJ.
WWE could go the direction of turning the thing into one massive joke and have the admirer simply be Hornswoggle. It's just the kind of thing that seems like it would appeal to Vince's sense of humor. Think about it: Kaitlyn, the former female bodybuilder & fitness model, and a woman who doesn't have the traditional bikini model look more common to Divas paired up with the 4ft 4in, 130 pound "leprechaun". Vince would find that hilarious.