The desire for fixed-aperture and/or large-aperture zoom lenses is noticeable.
With more than a third of the votes, the 70-200mm f/2.8 DG easily dominates the ranking. The current version is no slouch, but photographers are now used to the Global Vision quality. A Sigma 70-200mm f/2.8 DG OS HSM Sports would get a lot of attention provided that it can offer at least the same optical and mechanical quality as the Canon and Nikon “equivalents”, and of course at a lower price. Note that in the first poll, asking what lenses people would like to see from Sigma, a Global Vision update to the current 85mm f/1.4 DG EX ranked first.
Next up is a slower lens but with a very useful range: the 100-300mm f/4 DG. The affordable EX version was popular among nature and sports photographers on a budget. Sigma already offers a 120-300mm f/2.8 − since the 70-200mm range is often declined in two versions (f/2.8 and f/4) to satisfy the various needs, the same could be done for the 100-300mm range.
The 50-100mm f/2 DC comes just after. Interestingly, a new version of the recently discontinued 50-150mm f/2.8 DC got less votes, so quite a few photographers are willing to trade reach for more light-gathering capabilities. The result is a lens that would nicely complement the 18-35mm f/1.8 DC Art.
The 70-300mm f/2.8-4 DG is sure to attract those seeking for more reach than what 70-200mm can offer, while not compromising too much on the maximum aperture, and keeping price, size and weight at reasonable levels.
I’m surprised the 50-250mm f/2.8-4 DC did not get more votes. On paper, it looks like a fantastic workhorse lens, but it surely is not nearly as exciting as the aforementioned ones.
Last, the good old 70-300mm f/4.5-5.6 formula does not seem to do the trick anymore. With the Global Vision series, users are growing accustomed to being offered nicely specced lenses at keen prices, so they are naturally asking for more (like we can see above).