A music-related expansion pack - one with lots of different instruments, including accordions and modular synths that sims can craft, using multiple oscillator, envelope, lotsa other units that one can use to customize the machine. Maybe make it so players can make their own compositions and share them. It could even ship with a Robert Moog or Wendy Carlos expie sim. Maybe some samplers, drum machines, electric guitars and the like?

I think it'll be some kind of stuff pack of appliances with functionality like a dishwasher and a washer and dryer. But I hope it's Seasons >.> I was one of those people who got into Sims with Sims 3 and never understood why Sims 2 players wanted seasons again so darn bad, and now I'm completely in agreement with them! Game just isn't the same without holidays.

I hope it'll include aliens and customizable worlds, like maybe you could make a Master of Orion II style colony world and populate it with aliens of your choice. I'd go with the Elerians because it's easy to make them even in Sims 2 - all you need is some light blue/purple/greenish skin, custom hair and eyes, and pointy ears. Most of them would be athletic and have a mean streak. I'd love to be able to make some custom props for the world, like the Astro University, Robo Miner Plant, Automated Factory, Research Lab, etc. There are so many possibilities with that game and it's a pity that lots of people don't see them yet.

But I'd totally go for a musical expansion pack, especially one with lots of instruments that can be customized, and perhaps some physical modeling instruments with settings you can edit and step-sequencers, and of course, the ability to share your patches and compositions. This would really help sales a lot, especially for electronic music composers like myself.

Another idea would be injuries and disabilities. Maybe have sims who use wheelchairs or hearing aides, and blind sims, who if selected, will only have a very limited visible field around themselves, or even a wire-frame or sonar-ish 'visual' field, a la 'Bat Boy'.

I guess the first EP will be nightlife themed. Why do I think this?

Because a while ago (months!) one of the Simguru's was asking via twitter what we loved the most about Late Night and what our favorite object was.

I never been a big fan of late night, so I hope it won't be the first EP.
Still hoping for a proper Open For Business and Generations EP to be first.

The first EP will most likely come March 2015, and the announcement will be most likely somewhere mid November. (if looking at the history).

Before the EP's I'm sure there will be store/premium stuff already and maybe a Stuffpack.

My guess is a neighborhood pack that brings businesses and multiple job locations so we have a choice of which business to work for within a career for instance Landgrab Labs and Sim Science that compete for your employment with diferent pays and perks

Lots and lots of musical instruments, stuff like that, and maybe new crafts like knitting and crocheting. Possibly pools as well, but for any kind of new engine, there are going to be some kinks to work out. I would absolutely love to see customizable instruments, modular synths that you can build piece-by-piece and connect in different, fun ways. Maybe make some FM-style drums and percussion. I love to play around with virtual trackers and virtual modular synths, and this could attract a lot of remixers who are into composing songs with games.

This is exactly what they should do first. :lovestruc They could maybe call it something like "Familytime" and maybe they could add some new objects like boardgames etc. for the whole family to enjoy.

From there I couldn't care less what they come up with. But I'm afraid of them just starting to sell smaller stuff packs in TS4 store and not releasing any traditional EP's anymore. I doubt that you could buy a totally new lifestage like toddler from TS4 store..