Honestly I'd rather them have less "stuff" in the game and more variety in interactions and situations. Sims 3 really fell apart after a few hours for me because it was so boring. All you do is grind out stats for hours, and then grind out a job for money, and then spam 2 conversation options that work over and over with someone until the meter is full. Its all pretty boring.
That being said, I'd really like to see the return of multiplayer to the series, it really doesn't make any sense to exclude it these days. Also a faster fast-forward would be great.