Have to say I wasn't a huge fan of River Song, that said it would have been annoying if this major relationship in the Doctor's life pretty much all happened off screen so I don't have a huge problem with her showing up again, aside from the fact that she shows up so early in Smith's tenure. Be interesting to see what sort of chemistry they have, especially since the reason 10 was her bitch, as someone put it, was because she knew everything about their relationship and he knew nothing-I'd imagine the footing will be more equal this time...hell if anything the scales have tipped towards the Doctor, he knows what eventually happens to her 
