What do we think/want the next big project from Turtle to be after the roadmap?

Just looking for wishlists and peoples thoughts here purely out of my own interest and excitement for the future.

We've all seen the roadmap, so we've seen what's coming this year, but what's the next big thing we're hoping for? I'm looking for ideas on the scale of the Mysteries of Azeroth expansion to questing, the class overhauls and 2.0 client.

I was just thinking about how cool another talent tree for classes would be, doesn't need to be gameplay redefining (vanilla ones don't tend to be) but could offer a fresh leveling experience and be a more Turtle-esque alternative to a new class as I known they're keen to maintain the same core as OG vanilla.