Sorin's Ultimate and RIP

[Secretly.A.Bee]

So, I was playing magic against my girlfriend when an interesting scenario came up. I'm playing UWr Miracles and she's playing a BW SorinBlade list. I have RIP in play and she's closing in on being able to Ultimate off Sorin. Now, it wasn't relevant in the game, but it got us wondering, how does that pan out? Here is Sorin, Lord of Innistrad and here is Rest in Peace.

Will Rest in Peace take away whatever Sorin kills before he gets a chance to bring them back, or will Sorin's ability fully resolve and bring back the (up to) three creatures/planeswalkers first?

-ABC

[Megadeus]

I believe that since the things never hit the graveyard, they never return

[Malchar]

With rest in peace on the battlefield, nothing will ever go to a graveyard. Sorin's ultimate won't be able to return anything from there.