Ohh, I love a lot of the ideas here. I'll try and go for different ideas with mine.
Get To Work: Having your own retail store at home, like in Open for Business.
Get Together: Adding toddlers to clubs, so we can have toddler play dates at the park.
City Living: More festivals.
Cats and Dogs: Small pets, including an overhaul on fish and frogs. Take care of them like you can in Sims 3.
Seasons: New and improved PlantSims.
Get Famous: Tabloids and gossip. Sometimes, they'll be based on real incidents in games - like you picking a fight with someone, or the time you wet yourself in public. Every so often, a false rumor will be started about you, and it could hurt or hinder your reputation if you don't actively fight it.
Island living: A surfing skill and an associated competition. Train your body and mind through practice, then compete to win money or rare items.
Discover University: Active classes. Let us chat up our teachers, work on assignments with our fellow classmates, skill-build, listen to lectures and use our extra time to get a head-start on homework.