I went with animal, nature, and weather. To me, those are the core of the class--I always saw control over the classical elements being more of a Wizard thing. I think the shaper aspect should be a paragon path. On the whole, I'd conceive of the Druid as a Controller, drawing from the Primal power source.
The way I'd break those down:
Animal: this'd be a class feature, like Animal Empathy from 3E. Also some animal-based utility spells like minor shapeshifting, sharpened senses, and so on.
Nature: this'd be both a class feature (like Woodland Stride and Trackless Step from 3E) as well as a focus of the Druid's spells (Control spells like Entangle and whatnot). Utility spells like healing/regeneration.
Weather: also a class feature (resistance to elements) as well as spells (direct damage and AOE spells, like Sleet Storm and Call Lightning). Utility spells to shield from weather.
Rituals can cover classic Druid abilities like regional weather control, rat plagues & crop blights (or boosts), waterwalking/breathing, speak with plants/animals, awakening, even reincarnation. Also cover the summoning aspect, but in this case instead of summoning from some outer plane, you'd instead call an animals that's already in the region--and the animal would head your way, arriving 1-4 hours later. Lastly, I think it makes sense for Druids to be able to enter both the Feywild and the Shadowfell (death is, after all, a natural process).
For ability scores, I think it'd be cool if Wisdom drove the nature-based spells (you're in tune with and empathize with nature), and Charisma drove the weather-based spells (you impose your will over the weather, and force it to do your bidding).
That'd lead to two different flavors of druid. The receptive tree-hugging hippie druid, or the aggressive lightning-calling eco-warrior druid.