I'm getting dangerously close to GAS (Gear Acquisition Syndrome), as I've just purchased a dream lens (the Nikon 70-200mm f/2.8 VR), and now I'm thinking hard (probably too hard) about whether I should sell a couple other lenses and get a nice f/2.8 wide angle zoom lens.
The Nikon 70-200mm f/2.8 is an amazing lens (D3, 70-200mm @ 70mm).
I know that lenses don't define pictures (nor do cameras!), but 95% of my shooting is indoors, and most of that is without any artificial light... meaning a fast lens is never fast enough. I often use a 50mm f/1.4 prime (my 'light vacuum' lens), or a 35mm f/1.8, both of which create pleasing photos on my D7000. However, I've almost always wanted the ability to zoom, because moving back and forward isn't always an option, and switching lenses is a pain.
I bought an 18-105 VR lens, thinking VR could help me get past the slow f/3.5-5.6 aperture... but alas I'm still not happy with this lens. I fear that I won't be satisfied until I try out and acquire either the Nikon 17-55 f/2.8 DX lens, or the 24-70 f/2.8.
I've been reaching out to some fellow photographers on Facebook and Twitter, and gotten some good advice, but what do you think? I'm probably going to look for a used copy of the lens to save 30-40%, and I'll probably end up selling a combination of primes (I have the 35mm f/1.8, 50mm f/1.4 and 180mm f/2.8 right now) to fund this new lens. I would probably end up selling the 18-105 VR as well, as I don't think I could ever go back to more than f/2.8 once I dip my toes in that water :).
[Aside] Another cool photo resource I found recently, which explains the Nikon AF system used in the D7000 quite well, better than Nikon's own manuals: D7000 Focusing Guide. (I was always a bit confused by the different AF-C modes and zones... and it'll be fun to try them sometime at a sporting event).