The other things that've been mentioned more than once are a) the Medusa cascade (I'd bet the bank on this being relevant) and b) all the bees disappearing on Earth. And, I mean, of course there's the whole parenthood/families theme, but that one's obvious by now.

I don't see Rose being set up to be the next Doctor - I like the reading of the "Doctor!" "Donna!" call, but I just can't quite buy it - but I do agree that Grandpa Wilf knows more than he's saying. :D

Doctor Who is the best conspiracy-theory fandom EVER!