The addition of Live Traffic info on the Sat Nav is a great step forward and with development i am sure it will become an invaluable tool for drivers. What doesn't quite work at the moment is the scenario where I am setting out on a 3 hour journey to london, and due to congestion somewhere close to my destination, the tom tom wants to re-route me.. But by the time I will get there, the chances are that the congestion will have cleared and my diversion would not be necessary.
It would be useful to have more information and details of the traffic problem at the time it crops up and, with an indication of how far away it is, ask if you want to postpone the decision of whether or not to re-route.