Sorry, they HAVE build the Duke from scratch. They have a new 2011 and now a 2012 frame. with input from Rossi and JB) They have a new engine with lots of power. The 2011 Duke is much faster then that of 2011, wich was only average. It has the same top speed like the rest. But the new Duke is not faster or better then the other motogp bikes. Rossi will dare to compete when the the Duke is considerable better then the others. Like he was used to with the help of JB. With the present competition that will not happen.
After looking at the results and the developments so far, it's clear that neither Rossi nor JB possess the right experience to develop the Desmosedici fast. It might take them the whole season. All their experiences have been with Japanese bikes (Honda and Yamaha), which are more or less smiler. Hopefully, we can see good results next year.