The limited editions all come with DVDs that are listed to have a music video on them but no other information in known about their contents.
The regular editions will be the usual for Hello!Project releases with just a CD and the first press editions coming with a trading card/photo (one for each member and a group shot that is randomly selected to be included).
Despite the loss of Shimamura Uta the group looks to be moving forward at full speed. While the wound of her leaving is still fresh it is probably for the best that the group does so or they could risk losing their early momentum. Though I cannot help but think that doubling the number of LEs is partly to try to make up for Uta no longer being in the group, so it does not dip much in sales.
That said I wonder with their being four if they will be member exclusive, minus Momoko as she has the unique playing manager role. So each of the four get featured on one of the LEs. I could see it happening as they already divided the group in half for the debut single DVD extras with the Q&A they did with them for it.
But I guess the closer to the release date the more shall be revealed, but until I know what the contents are I will be holding off on pre-ordering. I cannot afford four LEs, especially not with a new Morning Musume '15 single heavily rumored to be coming out very soon after this release. But thankfully with H!P I don't have to worry so much with LEs going out of print before the release date like with Johnny's.