You never know. They could release a Pink Spyro and you won't even know it. Then by the time you find out, it's on eBay / Amazon for $299.99 and you're like, "What?! There was a Pink Spyro?!"
We can kind of assume and speculate on what's coming out. We know at least there should be a new giant, a new LightCore and at least 3 S2 Skylanders. After this wave, all the new ones will be out (Hot Dog was the last one)