Marvel Comics have announced that the 600th issue of Captain America is going to break with tradition and be released two days early, but what's so special about June 15th? Well, perhaps it's all to do with news embargoes...
The announcement of the new release date for the issue - the first time in more than a decade that a comic has been released on a day other than Wednesday (Holiday bumps aside) - doesn't give a reason for the shift, but it's worth noting that the new release date is also the day that, according to Marvel, their new series Reborn will "be receiving nationwide press... possibly on par with the media coverage we received during Civil War".
Previously, rumors about Reborn - which, so far, has received no advance publicity or even explanation, in a move that has angered retailers who are having to place orders (and, as said orders will be non-returnable, spend their own money to gamble that the series will find an audience) without information on the contents of the series - have centered around the potential return of the original Captain America, dead since 2006's Captain America #25 (No, there haven't been 575 issues of the comic in the last three years, in case you're wondering; #600 is really Vol. 3 #51. Don't ask), but with the recent release of a preview image for Cap #600 featuring a character from the parallel Earth-series Heroes Reborn, it's now possible that the title may refer as much to the 1990s "Reborn" line/Earth as any specific character. Either way, expect to find the start of Reborn's story in the early release of Captain America #600.