Thanks for the feedback! I have heard good things about that lens and I'm thinking of investing in it. As well as an updated telephoto lens (I still use the kit lens that came with my old D80).
Go for the fixed lens first. A better telephoto lens is all well and good, but to get a remarkably faster lens than your current one, you'll have to spend a lot.
I have a 50mm 1.8 Minolta lens, which stays on my camera almost exclusively, the only time I put the telephoto on is if I'm going to a baseball game or something where I'm getting great light. In fact, my 50mm feels more like a portrait lens, and I'm considering a 35mm lens as well. Don't be scared of going with a used lens too, especially fixed lenses.
Sorry for the hijack...