Ok, let's see:
- March 15 is just a placeholder date, obviously. These games will release sometime in march but they don't know when. Also they priced the games high as possible to avoid angry customers ("But you said it would be 40$").
- April 2 are all Ubisoft games so either they don't know Ubisofts US release dates yet or these titles will be pushed to Q2 in America.
- June 2 is also a placeholder date for Nintendo games released later than "early June" (that's what they said at their press conference).
Other dates are either guesses or preliminary dates that are still subject to change.
Gamestop is so clever
Edit: Having Pilotwings for launch would be amazing. I've been waiting for a release date ever since its announcement.