I have been told both March 15th and April 1st by the same SA! She said they are trying to get it in early, but cannot confirm that currently.
On a side note, much of this information is already listed in both the comments and photo sections of the Spring/Summer Summary threads. That is where you can find the most up to date info on new releases from this collection. So rather than starting a thread you can often find it right there along with some great conversation! LOL! I hope that helps!