New in PCSWMM 2009 version 3.4 is an anti-aliasing feature that improves map rendering of all layers (raster and vector). I could describe it in detail, however I think these two screen captures communicate everything that needs to be said.
Anti-aliasing turned off (a la older PCSWMM):
Anti-aliasing turned on:
Notice the effect on the background DOQ, the pixelation of the cars and at the edges of the buildings is smoothed. The jaggies on the conduit borders are also smoothed, making the whole map easier on the eyes. Also notice the ability to flow SWMM entity labels along the entity path, which really becomes a nice feature when used in conjunction with the new anti-aliasing feature.