Ok, so the accepted theory is that there are two teams, two HOHs (one from each team), and they each nominate two from the other team. Battle of the Block determines which set of nominees are official, etc.
But then, why win HOH? You aren't guaranteed safety and you're not guaranteed to get a target out. But you are guaranteed blood on your hands. Great..
What's the incentive to win HOH then? My guess is that the Blood vs. Water twist is legit -- the incentive is to protect your loved one that is on the other team. It's a perfect tie-in with BvW.
You can see the green backdrop of the new DR in two of the hanging pictures. It's from The Talk, and will be shown in a future episode where they enter they house.
Here's something I found interesting -- Big Brother Network, a popular BB blog that interviews the Houseguests each year, said: "Think you know what’s going to be revealed? Just wait!" about the cast.
That's so exciting!! I actually hope it's a veterans vs. newbies season, with all 16 revealed tomorrow (including the vets).
They each nominate two HGs from the OTHER side. Those two sets compete in the battle of the block competition, then the losing pair is nominated.
HOH isn't safe because the other HOH can nominate them. Battle of the Block replaces Have-Not (like the Coach competition did). Whether or not there are still Have-Nots is unknown, they just posted the third bedroom on CBS. It could be a Have-Not room, but they usually don't reveal it.