If you have access to a pro camera store near you, just go and play with it - as well as the 1.8. Once you look through the 77mm glass, any questions as to its worth will be put to rest. While primarily designed as a portrait lens, its ability to see in the dark makes it a beautiful low/available-light pj lens.
So, depending on your needs, and budget only you will be able to determine if it's right for you. As mentioned by "Clix Pix" there is rumor to an AFS update. However, if recent replacements in the AFS lens line-up are to be used as a guide for what to expect down the road, then it's fairly certain a new version will be accompanied via "G" series F-mount. If this effects you? Either way, its something to consider depending on your current body line-up, or near future ones. (Reference film bodies, and Nikon's new ff sensor with respect to fps, and px count/image size.)