I would upgrade to the D7000 or maybe even wait a bit to see if the D7000 replacement is announced in early 2013. I have never been a fan of the 17-55, mainly due to the weight, but also because it does not zoom farther. At 755g it is almost as heavy as a D7000 with battery, which is 780g. However, it is a high quality lens, and I know there are many happy users. Even if I did want that lens though, I would upgrade from the D5000 first.