Should slow dancing be base game instead of just part of one pack?

The fact that you didn't actually need the dance floors in order to be able to slow dance (just turn on some music and you can have Sims slow dance right there) is proof enough why slow dancing should be a base game feature. But like everyone else has already said, it won't.

Maybe in a few years from now if they need the slow dancing for other packs they'll "emancipate it" just like they did with the Seasons calendar.