It will run, but I wouldn't recommend it, even with 2GB of RAM. The hard drive is slow and the CPU doesn't help things much. Even with the 7200RPM drives, you're still asking for some pretty serious frustration. That said, a PowerBook is good to touch up or make some minor changes to a project while you're on the road. It's just not very productive for actual daily use. A $2000 PowerMac would be far more capable than a 15" PB.
If you're the patient and calm type, it's doable, especially if you need a portable and also need Motion and can't afford two computers 🙂.