It is there in the goodies folder and there’s also a Readme on how to install it. If you download from the net rather than have the install CD then be sure to download the additional content, since that is where it is located.
They note that you shouldn’t need it because the Lightroom’esque Output function in bridge is supposed to replace it. I think this is incredibly optimistic since the Output function has nothing that even remotely resembles Picture Package functionality. I’ll be the first to admit that Picture Package in previous versions of Photoshop was a mess, but it was better than nothing!
Even the layout generator in Lightroom, which seems vastly more advanced than the cripple-ware version that they put in CS4, doesn’t really provide enough functionality to do the job of Picture Package. Annoying because I use this feature extensively to layout prints on roll paper, and to optimize printable area. Ability to easily lay out multiple sizes and copies on one sheet is essential!
Sigh … other than that, and the incredibly annoying omission of auto-rotate to fit in the print dialog, CS4 is very impressive and they’ve done an excellent job on it.