here : NATIVE INSTRUMENTS: home
you’ll find a list of Intel-Mac compatible Software.. atm NI say this: they have no Intel code yet, but any new product will be „universal“, means PPC and Intel and they will offer updates for their software sooner or later this year starting with traktor and the guitar stuff, reaktor will also be converted in II/2006. the others will follow this year. most run under rosetta ,but they do not guarantee it will work.. anyway: it would be slow since emulating is always not the best for audio solutions..
they also say they will support PPC macs, (still)..