[upgraded my mac, so I post a new reply]
Computer type: iMac Intel 24"
Mac OS Version: 10.5.5
Processor: 2.8 Ghz intel core 2 duo
RAM: 4GB
Video Card (type, VRAM): ATI,RadionHD2600, 256mb
No real big issues, it runned fine. Except some area's where exceptional dark. So I used the shader bug to fix this.
Further, it runs very smooth. A map loads like in 2-3 seconds!! Wow!! Stability is good, no crashes at all.