Residential BW Planning

I am trying to perform some capacity planning for some of our residential pops, but the old calcs I used to use seem useless -- as they were adapted from the dialup days and relied upon a percentage of users online (~50%) and a percentage of concurrent transmission (~19%). My present scenario involves a micro-pop terminating 250 residences where users are expecting 4 mb/s. So I am looking for some baseline to begin at, so I am wondering what others are doing. Any thoughts are appreciated. Thanks --steve