Received news earlier today that sigma have announced the intended launch of a 200mm-500mm F2.8 lens, in both Canon and Nikon fit. I have already asked Ray Fitchett of Sigma UK for a look at one as soon as possible. As yet there is no announcement on price or availability.
Not particularly of interest to me as I shoot on EOS1D bodies, the Sigma DC lenses are designed specifically for the 1.5x and 1.6x image crop sensors, so things like the Nikon DSLRS or Canon 350D and similar.
Another new product announcement, that maybe of interest to me is the new Sigma DP1, the only downside is that it has no optical viewfinder and it could have benefitted from having a faster aperture lens especially as it is a fixed 28mm (equivelent) something like an F2 or 2.8 ( an F1.4 might be wishing a little to much.