IT will come back as a 2/2 morph of the impersonator and not as a shorecrasher copy.
January 13, 2016 3:06 p.m.
You will be stuck with a 2/2 morph creature. When it enters the battlefield face down, it is a new entity, not copying anything. It will be a regular Clever Impersonator face down, but with no mega/morph ability to turn it face up, so it'll stay is a 2/2 unless forced face up by some other means.
January 13, 2016 3:16 p.m.
If it is forced face up by Ixidor, Reality Sculptor or Break Open, your Clever Impersonator will be sent to the graveyard as a state based action for having 0 toughness, unless you have a static buff in effect that makes its toughness greater than 0. Since Clever Impersonator is already on the battlefield, turning it face up will not give you the chance to have it copy anything.