Sigma has announced four new lenses. Three of them are EX DG models with constant f/2.8 maximum apertures. (The "DG" indicates optical formulas optimized for digital cameras while retaining full compatibility with the 35mm film frame size.) These are:
A 24-70mm f/2.8 EX DG Macro
A 28-70mm f/2.8 EX DG (Sigma claims this is the world's smallest large-aperture zoom.)
An APO Macro 150mm f/2.8 EX DG HSM
All three of these lenses will be available in the following mounts: Sigma, Canon, Nikon D, Pentax and Minolta D.
Though the product itself is aimed clearly at hobbyists rather than professionals, we'll also note that Sigma has become the first company besides Olympus to offer a lens in the Four-Thirds format mount (which would currently fit only the Olympus E-1 camera). It's an 18-125mm f/3.5-5.6 DC zoom lens (which will give the same angle of view as a 36-250mm lens in the 35mm film format).
No pricing or availability information is given for these products.