While there have been many rumours, one seems to be confirmed. The theme of the seasons will, apparently, be "The Have and the Have Nots" or "A House Divided". This may be a season of both new people and returning houseguests. (Sigh)
The initial rumour was that there was a second house being built. This idea is unlikely, but it seems the houseguests will be divided into two teams and the teams will be playing against each other until a merge. This, of course, pulls from the idea of Survivor, but it really isn't the first time we'll see this in Big Brother. Season 6 automatically divided the house into the Sovereign Six and the Nerd Herd, if you recall.
Another side to note today is that the houseguests enter the house this evening. We will not get to know them for another 11 days however.