UnsameQ
lhs =!= rhs yields True if the expression lhs is not identical to rhs, and yields False otherwise.
See notes for SameQ. =!= =!= gives True if no two of the are identical. See The Mathematica Book: Section 2.3.5. See also: Equal, Order.
Further Examples
lhs =!= rhs yields True if the expression lhs is not identical to rhs, and yields False otherwise. 
=!= 
=!= 
gives True if no two of the 
are identical. 
