Nikon 24-120 f/4 VR

Just yesterday I was reading David Ziser's book (Captured by the Light -- review coming up) and was thinking about Canon's great lens lineup, such as its 24-105 f/4L IS, which seems to be a useful range (for full frame) and is not too slow. Well, Nikon just announced the 24-120 f/4 VR. Nice. I hope they have more cool stuff up their sleeve. Meanwhile for a 1.5-crop sensor, I would consider the Sigma 17-70 f/2.8-4 OS, which covers an equivalent range to the 24-105, and even has a wider aperture at the wide end.