Earlier today, Fan website bbspy posted that a brand new website advertising Official Big Brother auditions for Channel 5 was found. 

The Site (which is www.bigbrotherauditions.co.uk) only currently has two doors and is yellow and black. It says that auditions are starting soon. It also contains a link to Endemol UK and Channel 5. More Details will become available soon. 
Also still waiting is the website bigbrother.com which was previously used for a global website for Big Brother. The Site is now a test page with the words 'Big Brother.com Coming Soon' and contains the Endemol UK Logo. 

Also on friday, Channel 5 announced via Twitter that they will make a big announcement within the next few days but it is not sure if this will be for Big Brother.