I'm at work now, so cannot confirm the details too well, but to keep the prices the same as 2009 models for the 2010 models, they lowered the standard of parts etc on the Madone range (not the frame). I bought the 2009 4.5 but prefered the 2010 4.5 colour scheme but by buying the 2009 model I got a better bike for the same money. Off top off my head a 2010 4.9 madone will have the same or similar parts as the 2009 4.7 as I see the 2010 4.7 has virtually the same components as the 2009 4.5, but I have also just noticed their is no 2009 4.9 Madone and the components may be better than the 2009 4.7 as I see it includes Dura Ace as well as Ultegra.
My experience of the 4.5 is that it has been very difficult to get comfortable on it. I have a Trek 1.2 which is brilliant, yet despite the geometry being exactly the same between a 1.2 and a 4.5, they are like chalk and cheese and the 1.2 is far more comfortable. At the moment I am on my 4th sadlle, a Fizik Arione, and it seems to have sorted out all my problems, perhaps swapping the saddle from the 1.2 may have sufficed and then bought another if it did. Yet I cannot understand why both bikes have different saddle heights measured from the bottom bracket yet all dimensions are the same. Saddle too low on the Madone kills my quads and knees if set the same height as the 1.2.
The only other parts I had to change were the tyres as they were lethal and useless at cornering plus very puncture prone.
Apart from that its a brilliant bike and well recomended. Cycling opened a new chapter when I bought a Madone and would happily buy another