Oh god, how dare they! I think the GL one would have annoyed me more as it's more if a surprise within the story.Damn, yeah... If only that spoiler had spoiled the film's own in-film spoiler, then things would've been so much easier.
Or more confusing.
On a related note unrelated to this simulwatch, I had Spike's death in Cowboy Bebop spoiled by a critical US Amazon review, and Kamina's in Gurren Lagann by an Internet meme. "Thanks", The Internet.
A friend of mine once had the big twist of Death Note spoiled when it was the next epsiode he was going to watch. Its the most angry I'd ever seen him and was just glad I hadn't been the one to do it.