Everytime I think that a certain piece will be the final one for the line, SSC keeps surprising us with a new one although the cycle of new pieces being announced has slowed way down as others have already mentioned.
Even if this isn't the last statue from the line, based on the steep price increase of newer Dinosauria pieces and the competetion with Chronicles Collectibles JP line (which is doing really well), I don't this line will last more than 10 years since its inception.
Although there are countless dinosaur (+ prehistoric animals) fans around the globe and probably a majority of them purchase dinosaur collectibles at a regular basis, no matter how appealing the SSC dinosauria statues are, it is pretty obvious that these pieces are out of the price range for most dinosaur collectors, and are geared towards statue collectors.