Soulcalibur: Broken Destiny to have less polygons than its console counterpart, Soulcalibur IV; however, this doesn't mean a drop in the quality "visuals" the series has become known for. Namco recently showed off a comparison of the two Soulcaliburs, using Ivy and her voluptuous form to show off the seemingly lossless quality.
It appears that Broken Destiny will use not more than half the polygon count of Soulcalibur IV. The graphical disparities appear to affect clothing textures and shadow/lightning effects most of all. Still, with the PSP's relatively small screen it won't be too noticeable. That, and you'd be looking elsewhere, we think.