When the creatures return to play, they return as new creatures being put into play. They have no memory of being in play before. [Guildpact FAQ 2005/12/22]
Any Auras and Equipment on the creatures do not leave the game. They stay and follow the rules for being unattached Auras (going to the graveyard) or Equipment (staying play). [D'Angelo 2006/09/09]
If they are removed from play during the end-of-turn step, they will wait until the end of the following turn to return to play. [Guildpact FAQ 2005/12/22]
All removed cards will return, even if they are not still creatures. [Guildpact FAQ 2005/12/22]