Hideo Kojima has tweeted that it's difficult to show how immersive Peace Walker is through videos alone.
Using James Cameron's Avatar as an example, Kojima tweets about the next game in the Metal Gear series (via Andriasang):
"It's difficult to show the interest and freshness of Peace Walker through video. Cameron's Avatar was a huge hit because of the 3D video. That can't be communicated through text and a trailer. It's something you won't understand unless you experience it for yourself in the theater."
In another tweet, Kojima chats a bit about what might be a response to the "5" having been under consideration for Peace Walker.
"It's not that PSP is the main platform for the future MGS series. PW is a test to see what type of expansions are there if MGS is brought to a portable. We're not just rising vertically with development on next generation systems, but also horizontally, trying to expand gameplay."
Metal Gear Solid: Peace Walker hits Japan in April, and the US and Europe on May 25 and 28, respectively.