Layers Magazine has a great artivle on their blog about what you’ll need to make sure your computer is ready for CS4. One important note for mac users.... many of the applications require that you have an Intel processor... so keep that in mind.
“Working in tech, you almost take for granted being a gear junkie and having the most newfangled computer out there, but I’m sure there are a lot of you who want to make the jump that are unsure of what is technically needed, as well as other people out there that are ‘taking the plunge’ and getting the CS4 Suite in addition to a new computer to be able to hold it.”