A posting on 99mac (Swedish web site about Macs) details some tests performed on the new Dual-core G5's. Based on what they're showing, the DC 2.3's are neck-and-neck with the DP 2.5's... good news for macdom.

Also of interest on the same topic is Apple's latest G5 processor sheet (PDF) that details the specs on the new machines. Of interest is that the processors in the "Quads" have 1MB of L2 cache in them instead of 512KB in the ones that were tested in the aforementioned article.