I upgraded yesterday at noon (FedEx kicks ass), and i've tested out ever CS3 application i have with it so far. PS, AI, ID, FL, DW, BR, Acrobat....they all work flawlessly so far. Actually, they all run faster it seems. and it's way easier nowt hat i have each app set up in it's own space. Life is easy and uncluttered.
It bloody worked on mine. I did clean install (wiped my HD) and it worked fine.
only one problem - do NOT run Safari while installing CS3. Leave your mac alone until it's done. I assumed do not run anything at all while installing.