CS2 applications may work. My girlfriend still runs Photoshop, Illustrator and Indesign CS2 on her iBook G4 running Leopard and hasn't encountered any issues (so far).
On my MacBook, also running Leopard, Indesign CS2 crashes on start-up. Every time. 😕
The Web Premium CS3 pack seems to be up and running, though (I don't use Acrobat Pro much). 🙂