Good idea to keep the G5 for graphics as Adobe still is... well you know what.
Upgrade to the latest FCP studio kit and you'll be fine. Some apps are either Intel or PowerPC for some reason, make sure it has the Universal Yin/Yang logo on it if you want to use it on both machines.
Universal just means it'll work on both CPUs at their native 'language' eg. it won't talk to the G5 in Intellish or to the Intel in Motoroli.
I didn't try out a PowerPC plug-in on an Intel machine yet so i can't tell how 'bad' that'll be.
Frank