April 1st is a filler. Check a calender. Notice that April 1st falls on Sunday? Most games in the US release on Tuesdays. Gamestop will use the 1st or 31st of a month as a filler all the time. Should see the number of games on Gamestop.com with a release date of December 31st.
September 25th is more likely because it falls on Tuesday. But here's an amazing idea. How about we wait for Sony to say when it's coming out? Wow what an amazing concept!
I'm gonna need a quality RPG for the Vita soon.