We're still waiting for an updated set of drivers for the Intel based Macs for the USB bridge chip (Silicon Labs CP2102).  Their Mac drivers only work with PPC, but we've been told that there will be a new set of drivers for the Intel Macs in a few weeks.  We'll post information on the availability of the new drivers as soon as we get them, but in the mean time, you'll have to use a PPC-based Mac or a Windows or Linux to interface to the radio.  Sorry for the trouble.

I managed to get my SRV-1 working with my MacBook. I had installed XP running on a Parallels virtual machine for another project, so just for the hell of it I installed the driver for the USB bridge chip on XP. Once I allowed XP to find and download some additional software, it was working. That surprised me, as I figured that Parallels was supplying a virtual USB port to XP and I guessed that the driver would probably need direct access to the hardware.  
 
Before I tried this, I got things working on a G4 Mac Mini, but now I can bring the SRV-1 to show off to the nieces and nephews when I visit my parents for thanksgiving.
 
OK, now to see if I can get it working on a Linux virtual machine - just kidding.

I solved the problem with running on an intel mac by replacing the usb dongle that the xbee transmitter plugs into.  It's a bit expensive, but I got one here:
 
http://www.newmicros.com/cgi-bin/store/order.cgi?form=prod_detail&part=XBEE- DONGLE-CARRIER&id=Be8Ea1hcx36W4E360s2l2I5D6DXnvvUN
 
Seems to work great and it's based on an FTDI chip instead of the silicon one.  FTDI has much better driver support including drivers for intel macs.
 
I just got it today, and it took all of 5 minutes to install drivers and get the python console working.