The next two codices have just been announced.... Space Wolves and Orks. Hmmm. I wonder which one will be first. (my guess is Orks from previous rumors). Also it does say that there is a will be packed with new content, although that does not necessarily translate to new models.
via the Warhammer Community
"both the Orks and Space Wolves codexes will be absolutely packed with new content for your games."