They seem exactly the same to me, but the wikipedia page on Superscalar CPU architectures says "While a superscalar CPU is typically also pipelined, pipelining and superscalar architecture are considered different performance enhancement techniques."
1 Answer
The wikipedia articles for pipeline and supercalar explain these quite good.
Simply put, a pipeline starts the execution of the next instruction before the first has completed - but instructions are executed still in series and in order.
A superscalar architecture can start two or more instructions in parallel in one core, and independent instructions may get executed out-of-order.