They're out of the game for consumer graphics now that picture quality is basically a moot point.
Back in the day when people were still using analogue connections (D-SUB) and tube monitors, Matrox had a clear edge in picture quality. I remember when the Millennium G400, Voodoo3 and TNT2 were pretty much neck-to-neck in performance. However, an increase in the resolution of your desktop beyond 1024x768 and it soon became clear for roughly the same money Matrox was giving you a double deal compared to the other two.
With DVI and HDMI the picture quality (not rendering quality, mind you) now completely depends on the monitor.