For those swapping systems:
Be aware that DRM'ed content will not restore onto a new PS3. (not a big deal, just redownload it, as long as it is still online - should generally be in your download list)
PS1/PS2 memory cards do NOT seem to restore. More annoyingly, there doesn't seem to be a way to back up an entire PS1/PS2 memory card image to USB storage manually, you need to copy each save game individually to a USB device. I haven't tested but I bet copy protected PS2 saves cannot be moved.
Game installations and the like will NOT restore, you will need to reinstall/redownload patches with the game disc.
Copy protected PS3 saves will NOT restore. (Whee, I get to play through Rock Band again!)
Don't bother making new users on your new PS3, just restore the HDD image. It will create placeholder users with your save data as best you can, you can rename them and enter your PSN info again. (For me, it made a bunch of users called "*User X" but it did manage to remember the names of some of the other users.)
Now if you'll excuse me, I have a shitload of PS2 saves I need to back up to a USB drive, one by one.