Remember that if you think you are having a serial number rejection issue, make sure that you are using the serial number generated from your Photoshop CS2 number by this page. The serial number rejection problems noted below, however, are still present.
In addition, an Adobe spokesperson tells us that a discrepancy between 2-day and 30-day trial terms has been resolved in a newly posted disk image - the software now correctly informs the user that s/he is installing a 2-day trial if a Photoshop CS2 serial number is absent. UPDATE: The Photoshop CS3 beta is now available directly from the Adobe Labs, nullifying our earlier coverage of a pulled link (below).