What is the black figure on the left?
Darth Plagueis, the Sith Lord mentioned in Revenge of the Sith
and written about in the Expanded Universe. He's already been released in Wave 3 of the Black Series, but (unsurprisingly) most can't find him. He's the hot chase figure in his wave assortment.
They just tossed some not-so-brand-new figures onto those shelves to spice things up and pad out the displays.