[Nikonfreak]

I suspect Sigma, as well as others...even Nikon, are constantly assessing what they perceive to be the market "need" and filling "holes" in their lineup as the priority.

Nikon, in hindsight, knew that if they wanted to really steal market share from Canon, they needed entry level DSLR's and other DSLR's in the lineup that are top performers in their class. The D80 and D200 really do that very well and Nikon really hit a home run with the 18-200 VR as a kit lens for the D200. They practically knocked it out of the park with a "one lens solution" that's quite good.

Fast forward. We all were wondering why all these consumer grade AF-S zooms. Well, the D40 answered that question as it only takes AF-S lenses. Now, Sigma could have a good upper hand here in that some of their lenses are of better quality than the consumer grade zooms of Nikon and Sigma does have the HSM line. That'd work. Nikon has opened the door for Sigma, and others, to come in and play on their turf. Heck, even Thom Hogan did his review of the D40 and spoke of the Sigma 30 f/1.4 and the Sigma 50-150 f/2.8 ...

The Sigma 30 f/1.4 has made me turn my head in that direction more than once and the Sigma 50-150 is something no one can deny that given the 1.5X crop factor .... well you get the picture...

The Sigma 100-300 f/4 has stood alone for a long long time where Nikon only played in primes with the 300 f/4, 300 f/4 AF-S and 300 f/2.8 AF-S I, II and VR

Nikon users have long since wanted a 100-300 f/4 or some equivalent...

Sigma 120-300 f/2.8 is a real attention getter for lots of working pros that would like that fast glass in a zoom.

Julio