rpy on macbook

Ruedi,

I have successfully installed the universal binary of R-2.3.0

You may want to install R 2.3.1 instead, there were a couple of quite  
important bugfixes (especially in the GUI).

and I'm  now trying to compile rpy-0.99.2 on a Macbook Intel Core  
Duo without success. Has anybody been successful in compiling rpy  
on an intel-based mac recently?

Not recently, but there were no problems except for one bug in Rpy -  
I don't know if that was fixed yet, but you may want to read

https://stat.ethz.ch/pipermail/r-sig-mac/2005-September/002275.html

If that doesn't help, please be more specific as of how your lack of  
success manifested itself, so we can actually help you.

Cheers,
Simon