New gameplay can mean a lot. Mini-games, masteries, story content... We can only speculate.
For new combat features, it could mean elite specs. I also like the idea of new weapons, which will offer existing professions new s1-5 skills. Scythes, Polearms, Flails, some kind of magic weapon, etc. May not be as flashy as 9 new elite specs, but it would expand build options.