Last night in BoT we had 6 BoE drop. Not sure if they up'd the drop rate or we got lucky. But I know some people farm just the trash for BoE's for themselves or the AH to make gold.
Well if you clear the trash up to Halfus, Switch to heroic, zone out or wipe...all the trash will respawn from the begining when you zone back in.
So in short.. you can force the trash to respawn instantly by switching the raid difficulty(then zone out/pull halfus and wipe/whatever) instead of having to wait for a soft reset.