To ring in the post-MGS4 era in a suitably festive tone, Konami had planned to hold a few big launch "events" in Tokyo tomorrow, some of those meet-and-greet, get-your-sleeve-signed deals. Now, though, due to "various reasons", it's cancelled them. With no explanation given, only a notice on the game's official website that it'll instead take place sometime later in the month. It could be down to Kojima and co. being a little pooped after the worldwide promo tour for the game, but there's always the chance Konami are a little spooked following the tragic events that took place in Akihabara earlier this week.
UPDATE - Seems it's most likely the latter. A Konami spokesperson has told Mainichi that "Because of the number of people expected to gather at these locations, we are taking safety into account".