The small little trick found by Jmes99 and posted on the PS Forums is simply performed by pushing forward your PS3’s console time as far as you see necessary. This will basically trick your console and the new “app style” PS Store into revealing content that Sony has scheduled for release later in the month.
Now while this is a pretty cool way to get a heads up on new PS Plus content before it is released, know that you can only see as much as Sony has already added to the store. A video demo of said glitch can be seen here, and if you want to check it out best do it before Sony find a way to block this little exploit. I wonder how long that will take.