I'm still a CS3 user who had planned to upgrade to CS5 this fall. Just got a job that would like me to deliver projects to a broadcast network who uses CS4 and they are not willing to upgrade to CS5. So for the time being I have to problem upgrading AE to CS4 for a couple months. I just can't find any way to purchase an upgrade from 3 to 4 on the Adobe site anywhere. Seems like only CS5 is for sale. Any recommendations?
The Production Premium and Master Collection editions of CS5 also come with After Effects CS4 and Premiere Pro CS4, to enable people with 32-bit operating systems to upgrade to the CS5 suite while still having a version of After Effects and Premiere Pro.
Perhaps this will help with your specific situation.
I'm on a Mac though. Will the Production Premium have the CS4s on the Mac version too?
I don't know of any relevant difference between Windows and Mac OS versions of the packages.