Should i get the Iphone 4s or wait for the Iphone 5

At the moment i have a blackberry bold but it is old and breaking so i wanted to get an iphone 4s as an upgrade. However, i do not want to be spending £34 a month on an iphone 4s when the iphone 5 comes out and it is much better. I just wanted some options and to see if anbody has a real insight into the new Iphone 5 coming out and whether it will be worth waiting for.