Marvel didn't publicize it at all; I was talking to the guy in my comic store just yesterday and all he knew was that there were rumors of a major Marvel character dying in the post-Civil War stories, and the double-sized Cap #25 was one of the main suspects for something major like that to go down. Which was why I asked them to put a copy aside for me -- shame the mainstream news sources decided to spoiler it before I (and probably many more fans) actually had a chance to read it.

Can you imagine if, back in 1980, the news had run with "Darth Vader is Luke Skywalker's father! Fans of the popular sci-fi movies can see this revelation in The Empire Strikes Back, which opens today!" -- I wonder if they'll do something like this on the day the last Harry Potter book comes out, too.

Marvel might as well have played up on it in advance, got a few more orders in like DC did with Superman.