Wow...I just read some of the older posts...and a few requests there have actually been fulfilled...like having pets...and there was a few others i cant remember now..but still... maybe the powers that be are aware of what players want...or at least visit fan sites to find out...
What I'd like to see is more random stuff...like accidents happening
I had a ball yesterday trying to make a pregnant sim be pushed down the stairs by her really evil ex-husband, having her tumble down, and land on a table with a candle on it...then having her lie unconcious while the house caught fire <- all for a storyline... not hectic stuff like that, but tripping on stairs or over furniture?
* Neat sims wiping their feet on the doormat before going into the house...but REAL quick, this could be annoying...
* Changes to the house and landscape...like in the sims 1, when you disturbed the ground the grass grew back later on... the terrain paints should fade with time, and the paint on the house should dull... If a room is on fire the walls and floor should go black... steps would break through after some time, and windows would be visibly dirty (Kaylynn would have to have a specific wash-day for windows!)
* Live-in maids, or at least having them stay in a room at the back.
* Kids pretending to be sick to stay at home
* Having parent-free households..(as previous posters noted!)
---and i agree with everything dutchdude posted!