Well, something fantastic has been data mined from the latest build of Patch 4.1:
LFD_RANDOM_REWARD_EXPLANATION1 = "The first seven random dungeons of this tier that you complete each week will earn you:";
If you haven't guessed already it looks like instead of only being able to complete one random heroic dungeon per day for Valor Points you will be able to complete seven in one week in total, be that on the one day or over several instead of only one per day.
So that means for players such as myself who play only a few days a week, for long hours at a time, that we can do all if not most of the seven random 'daily' dungeons for Valor Points all at once! This change will make a lot of people like myself much happier, and will hopefully alleviate the problems with wait times for dungeon groups with more people running more dungeon's when most people are playing eg Friday night and weekends.
Blizzard is finally getting things right!