Got my new MacPro today and I did a timedemo with "Normal" video settings. System has 1GB of RAM and the cheapo NVIDIA GeForce 7300 GT card. OS is latest so the system is up-to-date etc.
I downloaded the ioquake3 RC2 Mac build for testing and got 819.2fps with demo 1 (r_smp was 1 of course). Not at all bad and comparable with rates I had on my old dual 2Ghz G5 with a config similar to the "boli" one.