M.2 is basically a new style of sata port. It is a place to connect a SSD, resembling a ram stick, to the board that uses the PCI-e bus to transfer information making it mush faster. Should you get one for creative? I would say yes.
e-Sata is external sata connection. This connection is for external HDD/SSD's. IF you take drives from place to place or use an external drive for backup this is very useful if not then you will have no need for it.
EDIT: the M.2 socket allows for the PCI-e drive to be bootable where other drives Like the OCZ Revo drives that plug into a PCI-e slot can not be used as a boot drive.