As someone who recently came back to BB from Android, I'd like to see background apps/processes for a couple things:
1) Keep awake while plugged in (ie: GPS/music in car, device still goes to sleep after 5 mins) - could be an OS update/option?
2) Battery use/tracking - some sort of battery run time graph (see "battery use" in Android)
3) Data Usage / Tracking (not tracking what you're doing but just the amount of data being used...
These don't need a lot of resources, but if they needed to be in active frames then they're encroaching on the 8 "running" apps. Clearly some sort of running process manager would then be required, as background processes/headless apps could provide potential for misuse.